Evidence for public health on novel psychoactive substance use: a mixed-methods study

Article history

The research reported in this issue of the journal was funded by the PHR programme as project number 14/153/01. The contractual start date was in October 2015. The final report began editorial review in November 2017 and was accepted for publication in October 2018. The authors have been wholly responsible for all data collection, analysis and interpretation, and for writing up their work. The PHR editors and production house have tried to ensure the accuracy of the authors’ report and would like to thank the reviewers for their constructive comments on the final report document. However, they do not accept liability for damages or losses arising from material published in this report.

Declared competing interests of authors

Mike Clarke is currently a member of the National Institute for Health Research (NIHR) Health Technology Assessment General Board. Mark McCann has attended meetings and participated in activities with the Scottish Parliament Cross Party Group on Drugs and Alcohol, the Scottish Drugs Forum, Independence from Drugs and Alcohol Scotland and Addaction Springburn. He received grants from the Medical Research Council, Scottish Government Chief Scientist Office and the NIHR Public Health Research programme during the conduct of this study.

Disclaimer

This report contains transcripts of interviews conducted in the course of the research and contains language that may offend some readers.

Copyright statement

© Queen’s Printer and Controller of HMSO 2019. This work was produced by Higgins et al. under the terms of a commissioning contract issued by the Secretary of State for Health and Social Care. This issue may be freely reproduced for the purposes of private research and study and extracts (or indeed, the full report) may be included in professional journals provided that suitable acknowledgement is made and the reproduction is not associated with any form of advertising. Applications for commercial reproduction should be addressed to: NIHR Journals Library, National Institute for Health Research, Evaluation, Trials and Studies Coordinating Centre, Alpha House, University of Southampton Science Park, Southampton SO16 7NS, UK.

2019 Queen’s Printer and Controller of HMSO

Research questions

The research project had 11 research questions:

1. What are the types and patterns of NPS use?

2. What are the developmental pathways into NPS use and are they different across types of NPSs?

3. Is there an association between NPS use and health and social outcomes?

4. What are the patterns of NPS use as they relate to the patterns of other substance use?

5. Why do individuals with similar sociodemographic profiles and illicit substance use differ in their decision to use or not use NPSs? What are the emerging factors that contribute to this decision to use or not use NPSs?

6. Does the drug-taking profile of a NPS user differ according to age, sex and social class and across traditional drug-using groups?

7. What are the harms associated with NPS use and how are these different from those of conventional illicit substances?

8. What are the appeals of NPSs and how are these the same as or different from those of traditional illicit substances?

9. What are the risks associated with NPS use and how are these different from those of traditional illicit substances?

10. What knowledge and experiences do NPS users have of treatment services for NPSs and how do these differ from their knowledge and experiences of services for other substances (licit and illicit)?

11. How can the research findings be integrated into a framework to inform existing service provision/policy formation and educational initiatives UK wide?

Background

The public health impact of substance misuse is a global challenge. 1,2 Contemporary data reflect an increasingly graduated and fractured drug scene. The old dichotomy between a relatively small number of highly problematic drug users and a more significant number of recreational and experimental users is changing to a more complex and dynamic picture,1,3 with NPSs contributing to this fragmentation. NPSs are synthetic alternatives to traditional illegal drugs. Compared with traditional drugs, NPSs are inexpensive, relatively easy to source and frequently more potent. There is no universally accepted legal definition of NPSs. The United Nations Office on Drugs and Crime (UNODC)2 uses the term and defines NPSs as:

[S]ubstances of abuse, either in a pure form or a preparation, that are not controlled by the 1961 Single Convention on Narcotic Drugs or the 1971 Convention on Psychotropic Substances, but which may pose a public health threat.

UNODC2

UNODC highlights that ‘new’ does not necessarily mean original formulations (several NPSs were first synthesised many decades ago) but substances that have recently become available on the market. 2

In the UK, the Advisory Council on the Misuse of Drugs (ACMD) defines NPSs as:

[P]sychoactive drugs which are not prohibited by the United Nations Single Convention on Narcotic Drugs or by the Misuse of Drugs Act 1971 and which people in the UK are seeking for intoxicant use.

ACMD4

The European Monitoring Centre for Drugs and Drug Addiction (EMCDDA) adopts a similar definition, although some substances that are controlled in the UK fall outside international control mechanisms, for example methoxetamine. 5

Over the past decade, first-, second- and third-generation NPSs have been increasingly referred to in policy and research documents6,7 and these substances have been appearing on the drugs market at an exceptional rate. By 2012, the number of NPSs outnumbered the total number of substances falling under international control. The overarching legal term ‘NPS’, with numerous substances grouped under this single heading, is now out of date and is of limited use when investigating differential patterns of use and harm. 8 Recognising the need for a more refined definition of NPSs, the EMCDDA subdivided the market into five categories:

1. ‘legal highs’ – marketed at recreational users; could be purchased online and in headshops until 2016

2. research chemicals – marketed as being for scientific research purposes; sold readily online

3. food supplements – aimed at individuals seeking to enhance themselves physically or cognitively; available to buy online

4. designer drugs – manufactured illegally in laboratories and sold under the guise of illicit drugs [e.g. 3,4-methylenedioxy-methamphetamine (MDMA) and heroin]

5. medicines – sourced from patients or illegally purchased via the black drug market.

Novel psychoactive substances have been broadly categorised5,9 as ‘synthetic cannabinoid receptor agonists’ [e.g. JWH-018 (‘spice’)], ‘aminoindanes’ [e.g. 5,6-methylenedioxy-2-aminoindane (MDAI)], ‘synthetic cathinones’ (e.g. mephedrone), ‘tryptamines’ (e.g. 5-Meo-DPT), ‘ketamine- and phencyclidine-type substances’ (e.g. 4-MeO-PCP), ‘plant-based substances’ (e.g. khat), ‘piperazines’ (e.g. benzylpiperazine), ‘phenethylamines’ (e.g. Bromo-DragonFLY) and ‘other substances’ [e.g. dimethylamylamine (DMAA)]. 10

For this research, we too attempted to disentangle where possible the various NPSs (see Adley’s drugs wheel11 for further information).

Legislative context

Novel psychoactive substances present challenges for legislation and monitoring, researching and developing interventions. For many years in the UK under the usual system of drug control, individual drugs, or groups of drugs with similar chemical structures (‘generic definitions’), were placed under the Misuse of Drugs Act 1971,12 based on the assessment of likely harms to individuals and society. That system of drug control is a lengthy process, which involves evidence gathering and reviews undertaken by the ACMD. Based on this review, the ACMD makes a recommendation regarding whether or not to classify or schedule the drug, and what other approaches could be used (e.g. specific prevention, treatment and harm-reduction advice). In 2010, changes to this process were signalled when mephedrone, possibly the most commonly known NPS, was banned in circumstances that caused the ACMD and others to question if this decision was based on the best available evidence. 13 Shops and online retailers selling the drug labelled as plant food cleared their shelves prior to the ban. Since then, and because of the large increase in the number of NPSs identified,2 the UK Government decided that it needed new laws and approaches to NPSs. This resulted in the temporary class drug orders (TCDOs). These drug orders put substances/groups of substances under temporary control for up to 1 year after a rapid review. In 2014, an expert review was published detailing a new legislative approach to dealing with NPSs. Subsequently, a complete ban on ‘psychoactive’ products was introduced in May 2016; this approach met criticism from many experts. Prior to this, NPSs had been controlled for under the Misuse of Drugs Act 1971;12 however, it was not possible to continually update the legislative approach for classifying drugs at a pace matching their emergence onto the market14,15 and, therefore, a new approach was needed.

The Psychoactive Substances Act 2016 (PSA)16 defines a psychoactive substance as any substance that:

(a) is capable of producing a psychoactive effect in a person who consumes it, and (b) is not an exempted substance.

Contains public sector information licensed under the Open Government Licence v3.016

The PSA goes on to define a psychoactive effect as when a substance depresses or stimulates a person’s central nervous system and has an impact on the individual’s mental functioning or emotional state.

In passing the PSA, the UK Government adopted the policy approach implemented by the Government of Ireland, which introduced comparable legislation in 2010 called the Criminal Justice Psychoactive Substances Act 201017 in a context relevant to the present research.

The PSA focuses on penalising suppliers rather than consumers; indeed, those caught supplying NPSs could face a prison term of up to 7 years, and those being found in possession of NPSs for personal use are not criminalised. Nevertheless, many NPS users were highly critical of the legislation,18 as were other groups. 15 Particular concern was expressed over how a psychoactive effect was defined by the Home Office in the PSA.

The PSA definition is problematic given that any number of substances can fall within it, including flowers and incense. The ACMD highlighted this concern and produced an alternative version. They also warned that some form of revision would be needed to make the law enforceable. Furthermore, the association between the closure of headshops and reduction in use of NPSs is not supported by data from Ireland,3 where similar legislation has been in place for some time. As is the case in a prohibition context, it is likely that continued demand for NPSs will result in driving the substances underground, thus resulting in even less potential for quality control than existed pre legislative ban. This may lead to riskier patterns of sale and consumption, as again has happened in Ireland. 15

The EMCDDA’s analysis of the situation was that current practices needed to be continually modified if they were to address a drugs problem that was in a state of constant change. 19 In some European locations, including the UK, Ireland, Poland, Portugal and Austria, approaches to NPS control have been constructed on the basis of broad definitions of ‘psychoactivity’, with harmful outcomes not always being taken into consideration. 1–3

Any benefits, harms and unintended consequences, both short and long term, from the PSA and similar legislation will be evident only over a more extended period.

Market context

The marketing approach to NPSs was qualitatively different from that of other illegal drugs owing to the greater use of attractive packaging and branding. 20 According to Wallis,20 the effects of media attention on the NPS market are often counterproductive, leading to spikes in use. Interviews with key stakeholders (e.g. retailers, NPS innovators, enforcement professionals, policy-makers) suggested that the PSA was unlikely to affect the supply of NPSs through the internet/fast courier system. Reports in Northern Ireland after the legislation suggested that mephedrone availability was relatively unaffected, although drug purity had decreased. 21

Novel psychoactive substances also produced other innovations in the drug market. Shapiro5 noted that, serendipitously, the parallel growth of the internet was, for some, a very effective aid for producing and selling NPSs. On a global scale, users were able to interact and exchange knowledge about NPSs and their effects. In addition, it was evident that enterprising individuals had performed searches for patents relating to compounds that had been investigated by pharmaceutical companies but were no longer being pursued.

To avoid detection, encryption technology is reported to have been used when purchasing NPS drugs or their raw chemicals from Asia. 5 Retail order and shipment occurred from websites with payment through third parties [e.g. PayPal Holdings, Inc. (San Jose, CA, USA)]. Finally, the ‘dark web’ grew to house online black markets such as ‘Silk Road’; a high level of technical expertise was needed to access NPSs via this route using virtual currency (e.g. bitcoin). Despite NPSs being more readily available online, some evidence suggested that only a small proportion of NPS users obtain their drugs via online retailers. 22 Rather, NPS users often sourced from friends, dealers and headshops. Although they may not use the internet to purchase NPSs, many habitual internet users availed of the internet to research NPSs. O’Brien et al. 18 investigated the experiences of ‘cybernauts’ using an online survey (n = 183). Around 3 in 10 participants reported using NPSs within the previous week. Participants considered themselves to be knowledgeable consumers owing to their internet use; for example, the internet was the medium through which they gathered information about NPSs and, in turn, passed on their own experiences (e.g. harms experienced) to others.

Retailers have capitalised on the knowledge shared by these online communities and have even reported monitoring internet forums to gauge demand for different NPS types, adjusting their stock accordingly. 20 The relationship between NPSs and existing traditional markets is a highly complex one, and a temporal relationship between variations in the purity of traditional substances can be observed. 23 Other authors have documented the displacement effect of the various forms of NPSs. 24

Pharmacological context

From the pharmacological perspective, the level of innovation in the production of NPSs limits the knowledge of both the pharmacodynamics and the acute and chronic toxicity of these continually evolving substances. 25 Identifying individual substances bought via the internet or on the street is difficult. 26 Even when a new chemical is clearly and accurately identified, all too often there is little or no information on associated harms and suitable treatments. There is progress in studies aimed at assessing their pharmacology: individual pharmacodynamics and kinetics, toxicity profile, dependency risk and short- and longer-term threats to physical and mental well-being. 27,28

Furthermore, various NPSs are often ingested together or in conjunction with alcohol and/or other substances in an idiosyncratic way, adding uncertainties about the consequences of combined intake. 29 Synthetic cannabinoids (SCs) have also been examined in detail. 30

To assist in the identification of emergent NPSs, the Welsh Emerging Drugs and Identification of Novel Substances (WEDINOS) project was set up in September 2013. Prior to the blanket ban, results posted on submitted NPS samples have generated a reactive response, for example the invocation of procedures to also ban the next substance emerging from laboratories. Results from WEDINOS31 indicate how complicated the picture is, in that there is a cross-fertilisation between NPSs and other drugs leading to a more difficult screening and assessment process.

Against this backdrop of legislative, market and pharmacological challenges, we now examine the existing evidence base on the various NPSs as they relate to traditional drug use. This introduction is followed by a summary of available information on the assessment of NPS use in the light of potential interventions. Before we consider the extant literature, NPS contextual data (e.g. prevalence and death rates) are briefly summarised. A more detailed summary of NPS and other drug contextual data in UK regions is presented in Report Supplementary Material 1, Tables 31–38 and Figure 9.

Key messages from prevalence data

There is an incomplete picture of NPS use prevalence; nevertheless, available data indicate that NPS use is relatively low when compared with more frequently used illicit drugs (e.g. cannabis, powder cocaine, ecstasy), with NPS use tending to be higher in specific subgroups (SGs).

Data on general NPS use from nationally representative surveys are of course limited to recent years. In 2014/15, the prevalence of lifetime NPS use (mephedrone excluded) was 2% in Northern Ireland (Department of Health Northern Ireland)32 and Scotland (National Statistics Scotland)33 and 3% in England and Wales (Office for National Statistics). 34 There was a statistically significant reduction in the prevalence of NPS use in the previous year between 2010/11 and 2014/15 in two regions of Northern Ireland: South Eastern and Western Trusts (down by 1.4% and 1.1%, respectively, since 2010/11). 32 The estimate of the prevalence of lifetime NPS use for the UK from the European Commission22 survey was higher (10%) than in other UK national surveys, and was above the average prevalence rate for European countries (8%).

Data from UK misuse databases

The UK regional drug misuse databases provide an indication of recent drug use by problem users. Drug misuse databases in Northern Ireland and England/Wales report on a NPS category. In 2015/16 in Northern Ireland, 7% of service users with drug use problems reported NPS use [Northern Ireland Drug Misuse Database (NIDMD)]35 compared with 1.3% in England/Wales [National Drug Treatment Monitoring System (NDTMS)]. 36 A specific NPS category was not reported in Scotland [Scottish Drug Misuse Database (SDMD)]. In Northern Ireland, NPS use was much more frequently reported in the Western services than in any other areas. Weekly use was the most frequent form of use for those using NPSs, mephedrone, cocaine, speed, ecstasy and other stimulant drugs. The vast majority of users reported trying NPSs before the age of 25 years in Northern Ireland.

Deaths

In Northern Ireland, death by substances on death certificate statistics suggest that although deaths in which NPSs are implicated, are rare, they have become more common in recent years. 37 In 2015, deaths implicating NPSs were most frequent in Scotland (1.4 per 100,000),38 followed by Northern Ireland (0.9 per 100,000) and England/Wales (0.2 per 100,000). 39 In Scotland in 2015, the majority (77%) of the 74 deaths in which NPSs were implicated involved benzodiazepine NPS (e.g. etizolam). In research studies, deaths in which SCs, mephedrone and phenethylamines have been implicated have been reported. 40–44

Existing empirical evidence on novel psychoactive substances

Synchronous with the present study, Mdege et al. 45 were commissioned by the National Institute for Health Research (NIHR) to undertake an empirical and conceptual review of NPS to provide research recommendations. Focusing on the UK, their principal objective was to provide review evidence to be used in developing public health interventions targeting NPSs.

The study comprised a scoping review and narrative synthesis of evidence focusing on NPS use, associated harms and responses. Spanning the decade 2006–16, the authors examined Google (Google Inc., Mountain View, CA, USA) and relevant websites and online drug forums, and contacted experts on NPSs. Their research included primary and secondary studies detailing relevant research or discussion of key research. They also developed a UK-focused conceptual framework detailing an evidence-based public health approach to NPS use.

Using a scoping review, Mdege et al. 45 identified 995 articles, the majority of which examined the health-related adverse effects of NPS use at the individual level. They highlighted that the expanding literature on the NPS phenomenon is primarily clustered around four key areas:

1. Surveys and surveillance studies.

2. Qualitative work that focuses on the harms associated with use.

3. A limited number of systematic reviews centred on harms.

4. Literature that seeks to evaluate policy responses to the NPS phenomenon. There are also clinical guidelines based on the evidence, such as those of the Novel Psychoactive Treatment UK Network (NEPTUNE). 46 They conclude that the literature is characterised by being early in its stage of development and lacking in data to directly inform an evidence-informed public health response to NPSs. 45

Regarding survey data, there are 29 identified studies that assessed NPS use prevalence in the UK. The authors usefully summarised the findings of the prevalence studies in tabular form. These included results from the Crime Survey England and Wales (CSEW), the Scottish Crime and Justice Survey (SCJS), the All Ireland Prevalence Study (AIPS) and a range of additional European surveys and school-based surveys. They also included a useful summary of systematic reviews uncovered by study name, study population, NPS type and methodological characteristics. In the UK, nationally representative prevalence surveys have focused largely on mephedrone, with data on other NPSs much less developed. More detailed data covering motivations and patterns of use tend to be restricted to a small number of qualitative studies.

Age and sex trends

The prevalences of lifetime NPS use in young people [defined as people aged 11–15 years (in England and Wales) and 13–15 years (in Scotland)] in England and Wales (2.5%)47 and Scotland (2.0%)48 are comparable. In England, NPS prevalence was 10 times higher among 15-year-olds than among 11-year-olds (5.0% vs. 0.5%, respectively). 47 Similarly, in Scotland, 1% of 13-year-olds and 4% of 15-year-olds reported NPS use. 48 Although NPS use was marginally higher among males than among females in the Scottish Schools and Adolescent Lifestyle and Substance Use Survey (SALSUS) (2% vs. 1%, respectively),48 this pattern was not evident in the NHS Digital survey47 nor in the survey by the European Commission. 22 With a broader definition of young people (e.g. people aged 16–24 or 15–34 years), NPS use was around two to three times (4–7%) higher in younger than older adults across all UK regions. Some variations were possibly attributable to the use of different definitions of young people. 32–34

At-risk populations

Studies specifically designed to measure NPS prevalence have not examined SGs other than in standard demographic groups (e.g. age, sex). Research has highlighted higher prevalence rates among specific populations than at the wider population level, including people with eating disorders,49 mental health inpatients,50,51 men who have sex with men (MSM),52 prisoners,53 the homeless54 and club attendees. 55 Although these prevalence rates may not give precise prevalence estimates for these specific groups, they do indicate that these groups are more likely to use NPSs. Among those with eating disorders, patients with a history of self-harm and bingeing/purging were more likely to report NPS use. 49 Given the high prevalence of eating disorders in females, this factor may play more of a role in female NPS use initiation. A study of mental health patients – individuals who were younger, male and had a criminal record – reported higher rates of use. 50 Evidence suggests that mephedrone (41%) is the most popular NPS among club attendees, whereas lifetime prevalence for the use of other substances was less frequent [e.g. methylone, 11%; methylenedioxypyrovalerone (MDPV), 2%]. 55 Almost all mephedrone users (94%) reported use in the previous year and most (80%) reported using NPSs within the previous month. In a sample of patients at two sexual health clinics, Thurtle et al. ’s52 study revealed that monthly use was low (1.6%) in the total sample and particularly low in 16- to 24-year-olds (0.3%). However, among HIV-positive MSM, Chung et al. ’s56 case review found that 24% reported lifetime mephedrone use. Bourne et al. 57 describe reports of MSM in London using mephedrone in combination with gamma-hydroxybutyrate (GHB)/gamma-butyrolactone (GBL), using these ‘chemsex’ drugs during sex, often involving groups and adventurous sexual activity (e.g. ano-brachial intercourse).

Motivations for use

A systematic review focusing on international surveys of SC use found that motives for use are often centred around perceptions that SCs are safer than other non-cannabinoid illicit drugs and that it is easier to avoid detection in drug tests while still enjoying a ‘cannabis-like’ high. 40 Within the UK portion of the Global Drug Survey sample, Winstock et al. 55 found that motivations for the use of methoxetamine, relative to those for ketamine, were centred around easier access, less damage to kidneys or bladder and a preference for the drug’s effects. Users of mephedrone often report pleasant effects of the drug, such as euphoria and a sense of well-being. 21,58 Another study focused on salvia; users of this NPS sometimes experienced pleasant hallucinogenic effects. 59 Motives for use do appear to vary by population; for example, among prisoners, the main reasons for using SCs were to evade drug detection, to help pass time and for relaxation. 53 Among the homeless, NPSs are often viewed as being a less costly substitute for alcohol and other illicit drugs. 54

Adverse effects

In contrast to the limited body of research on motivations for NPS use, there has been more focus on the harmful impact of NPS use, as revealed in the recent review by Mdege et al. 45 Systematic review evidence suggests that frequent side effects of NPS include psychotic symptoms, behavioural changes (e.g. aggression) and physiological effects such as changes in blood pressure, pulse and temperature. 60

The adverse effects are further summarised here according to substance type.

Evidence on prevention and intervention

The literature provides a useful summary of the research on, among other things, prevalence, motivations for use and adverse effects. Notable, however, is the absence of a knowledge base for the efficacy of any prevention/interventions for NPS use. To date, evidence has focused on providing guidance and advice on possible referral pathways and highlighting probable interventions. This is framed according to the symptomology, identified patterns of use, NPS class and specialist groups, including MSM and young people. To our knowledge, there are at present no completed or ongoing methodologically rigorous experiential trials or structured research evaluations of the effectiveness of pharmacological and/or psychosocial interventions for NPS use, either as a standalone drug of choice or within the unplanned or adjunctive drug context. 65

Chapter summary

This chapter set out the research questions of the present study in the context of existing evidence on NPSs. To accomplish that goal, we provided definitions of NPSs and summarised the legislative, market and pharmacological contexts of our work. Existing literature on a range of areas as they relate to the NPS phenomena was reviewed. This included reflections on current responses concerning interventions for the various NPSs as well as NPS vis-à-vis other substance use. Related to that effort, it became evident that there is a resounding need for more evidence within this area, which will help to articulate a clearer understanding of the complex nature of NPSs. The umbrella term ‘NPS’, used for legal purposes with multiple drugs grouped under this single heading, lacks utility for the practical purpose of exploring the markedly differential trajectories of use and harm. We seek in our findings to draw out a level of nuance that contributes to our grasp of the different categories of NPSs and their use by participants. In the research presented in the following chapters, we posit findings that can substantially contribute to the knowledge base on the use of NPSs, which constitute an ongoing public health challenge. We now present the methodology for the study, followed by our four substantive findings chapters.

Design

The study used a three-phase mixed-methods design, as summarised in Figure 1.

FIGURE 1.

Study design.

Phase 1 was a quantitative phase involving secondary data analysis of the Belfast Youth Development Study (BYDS) (see Secondary data source: Belfast Youth Development Study). A latent class analysis (LCA) using the 2039 BYDS participants who completed the ‘ever used’ drug questions at wave 7 (participants aged 21 years) was conducted to identify categories of drug use (including NPS use).

Phase 2 involved extensive qualitative analysis via narrative interviews of participants – sampled from BYDS, drug and alcohol service settings and prison – to explore trajectories of NPS use. NPS use did not emerge as a specific isolated class of drug use in phase 1 (see Chapter 3), which meant that robust conclusions could not be drawn about NPS use as distinct from other substance use through the quantitative analysis. By contrast, in phase 2 the narrative approach allowed rich data related specifically to NPS use to be obtained, allowing for highly detailed analysis of NPS use types. In addition, general risk factors related to polydrug use were identified.

In phase 3, the final quantitative phase, using the BYDS data set, the generalisability of the shared risk factor part of the model was tested, using the manual three-step approach66 to examine risk factors associated with latent class membership. In addition, adult outcomes (e.g. education, employment, health) associated with drug use were examined using weighted regressions. All analyses in this phase used multiple imputation to deal with missing data; extensive sensitivity tests were used to assess the quality of the multiple imputation models. Several integration analyses were built into the design to maximise the utility of the sequential mixed-methods design. Specifically, by integrating quantitative material with qualitative information, this allowed emerging findings to be further explored and cross-validated and later-phase methodologies to be refined.

Patient and public involvement

A professional liaison group (PLG) comprising key individuals from government, statutory sectors and community sectors and service users was formed. In addition, an international scientific advisory group (SAG) with membership from a range of key institutions in academia was set up. These groups were consulted at strategic points throughout the project and played an active role in the development of the project and interpretation of findings. For membership, see Acknowledgements. The research team also had regular contact with a local drug advocacy group [Belfast Experts by Experience (BEBE)]. This group provided valuable input at various stages throughout the study.

Secondary data source: Belfast Youth Development Study

This study used data from the BYDS, a longitudinal study of substance use during adolescence. The participants were young people who attended the target school year in post-primary schools in three locations across Northern Ireland. Schools were located in the Belfast conurbation, Ballymena and Downpatrick. The two townlands, Ballymena and Downpatrick, included rural catchment areas. The first data-collection wave took place in spring 2001, during the second part of the 2000–1 academic year; all pupils attending school year 8 in the schools that were taking part were invited to participate in the study. Parental consent was obtained by sending opt-out letters detailing the study for parents to return if they did not want their child to take part. In the following year (2002), data collection was repeated with the same methods for all pupils attending the successive school year 9 in participating schools. Data collection was repeated yearly until 2005 or school year 12 (participants aged 15–16 years).

The sampling strategy involved surveying all pupils in participating institutions from the targeted year group; therefore, cohort members entered and departed the study as they moved to or from participating schools. A number of schools participated in industrial action in years 4 and 5, and this led to lower completion rates in those years. Two further sweeps were carried out, one between the years 2006 and 2007; at this stage, some cohort members had left school, therefore the sampling strategy was adjusted to survey all participants for whom valid contact details had been provided. In addition, a number of schools and other educational institutions (including further education colleges and government training programmes, which were anticipated as destinations for school leavers from the original BYDS cohort) were invited to take part, and all pupils in these institutions were also surveyed. A seventh sweep of data collection was conducted between 2010 and 2011: all cohort members for whom contact details were available (n > 4000) were invited to participate through letters, e-mails, text messages or face-to-face contact. Cohort members were aged about 21 years at this stage. For more information on the BYDS, see Higgins et al. 67 and the Queen’s University Belfast (QUB) project webpage [www.qub.ac.uk/research-centres/darn/Projects (accessed 14 May 2019)].

The sample was further supplemented to include substance users recruited from carefully chosen sites (prisons, sexual health clinics and statutory and voluntary drug and alcohol services). The rationale for generating a further supplementary qualitative sample was threefold:

1. Elicit the most contemporary data available on the NPS phenomena (post PSA) and in the light of its fast-paced nature.

2. Maximise geographical coverage.

3. Seek locations with the potential for broad categories of user (e.g. prison, high-risk/complex users). This approach allowed us to capture a number of BYDS participants who were recorded in our data set as serving time in prison. We considered this expansion to cover prisons necessary as (1) our ongoing secondary data analysis showed a link between delinquency/criminality and polydrug use, (2) those in prison are a marginalised group who may not have engaged well with traditional drug and alcohol services, (3) the drivers of NPS use in prison are often unique to that environment (e.g. to avoid failing mandatory drug tests) and (4) our patient and public involvement (PPI) group discussions had indicated that the prison estate transcends geographical variation, thus maximising the opportunity to investigate the range in variations in types of NPSs. 40 Expanding our sample to include statutory and voluntary drug and alcohol services/sexual health clinics allowed us to broaden coverage to include high-risk, complex current users, who were uncommon in the BYDS sample.

The nature and extent of NPS use within the community derived from the BYDS sample, when complemented by knowledge gained from the prison estate, sexual health clinics and drug and alcohol services, provides a more robust and detailed evidence base to inform public health interventions. For this reason, the achieved sample was treated in a composite way. However, where relevant, our use of ‘setting codes’ in our analysis (see Analysis framework) was utilised to allow us to differentiate where experience was different according to site/setting.

Sample recruitment for the qualitative phase

The BYDS and supplementary sample participants were invited to take part in a narrative interview (see Belfast Youth Development Study sample and Supplementary sample for more detail on method) with two members of the research team, either on QUB premises or at a location more convenient to the participant (e.g. at a local community centre). The recruitment strategies for the BYDS, supplementary and prison samples were as follows.

Life course perspective

The life course perspective, an effective methodological approach, was used to examine the trajectory of each participant’s drug taking. This affords the opportunity to understand the individual circumstances of respondents, as their trajectories can often be non-linear and highly varied. Importantly, it permits the location of drug use within the overall context of the participant’s life, that is, their experiences are about much more than the drugs they use. Risk and protective factors were used as a shared theoretical lens for the quantitative and qualitative data.

Loeber et al. 68 proposed that the presence of protective factors can predict low probability of substance use and other adverse outcomes. Longitudinal and other studies have identified a number of well-established individual, family, school and community risk factors that are associated with alcohol and drug use throughout the life course. 69–73 At an individual level, risk factors include attitudinal, biological, cognitive, developmental, personality, pharmacological and social factors. 74 For example, cognitive risk factors for substance use include a lack of knowledge about the risks of substance use as well as the viewpoint that substance use is ‘normal’ and that most people are substance users. Resilience may interact with such risk factors in a positive way by minimising their effects. 71 According to the self-medication hypothesis, effective regulation performs a key role in development of substance use. 75 Psychological characteristics related to substance use include low self-esteem, lack of assertiveness and poor self-control of behaviour. In addition, it is clear that there is a positive relationship between the importance of pharmacological risk factors and the frequency and quantity of substance use by an individual. As with the effects of traditional licit drugs use, the effects of NPS use are likely to vary owing to individuals’ neurochemical reactivity to drugs, putting some individuals at a considerably greater risk.

A number of factors at the level of the family are important in relation to attitudes towards substance use and behaviour. Genetics have a part to play in terms of the development of substance use disorders, social learning is crucial in terms of modelling behaviour and attitudes towards substance use, and parenting practices can be influential in terms of parenting style and family environment. In the same vein, family-level factors can serve in a protective capacity in preventing adolescent substance use, particularly through the use of parenting practices that centre round open communication, boundary setting, monitoring and nurturing. 73,76–78 Finally, at the school and community level, the degree to which an adolescent bonds with school and community are associated with substance use. 78–80 Students who are not engaged with school, and perform poorly academically, are more likely to use substances. Adolescents who feel isolated from or unsafe in their communities are more likely to use substances.

This was the perspective taken within the BYDS, and statistical data were utilised to model pathways in and out of substance use within the context of a wide range of variables at individual, family, school and community levels (see Higgins et al. 67), all underpinned by an integrated theoretical framework based on the risk and protective factors noted. So, too, is this conceptualisation evident in the life course perspective central to the qualitative narrative interviews conducted. In these interviews, we were able to focus on the individual’s substance use and their individual characteristics and agency not only at a single point in time but in the broader contexts of their family, school life and the community in which they lived. This life course approach allows for consideration of past episodes and future projections. In using this technique, we had capacity to identify moments of disruption, critical events or turning points that were important to individual’s drug careers. The ideas of a crossroads, bifurcation or ‘point of no return’ are constant in these biographical narratives, which are detailed further in subsequent chapters.

Analysis framework

Our work required an integrated analytic approach, which necessitated both a deductive organising framework for code types (informed by our research questions and the quantitative findings) and a means to inductively develop codes. Previous researchers identified various code types. 83,84 Bradley et al. 85 documented an approach to data analysis that applied the principles of inductive reasoning while also employing predetermined code types to guide their data analysis and interpretation. These included (1) identifying key concept domains and essential dimensions of these concept domains, (2) relationship codes (identifying links between other concepts coded with conceptual codes), (3) participant perspective codes, which identify if the participant is positive, negative or indifferent about a particular experience or elements of an experience (e.g. a certain drug), (4) basic participant characteristic codes and (5) setting codes (basic information on specific sites).

In summary, Bradley et al. 85 posit that conceptual, relationship, perspective, participant characteristic and setting codes collectively express a structure appropriate for generation of three things: (1) taxonomy, (2) themes and (3) theory. They suggest that conceptual codes and subcodes facilitate the development of broad taxonomies. Relationship and perspective codes facilitate the development of themes and theory. Intersectional analyses with data coded for participant characteristics and setting codes can facilitate comparative analyses. We utilised a similar approach, which allowed us to generate the four-group taxonomy while also teasing out important themes and theory through our analysis.

Taxonomy development

The team utilised the five-code-type framework outlined in Analysis framework. Using the concurrent coding process across four team members, basic participant characteristic codes and setting codes (basic information on specific sites) were constructed and cross-checked across the team members. Characteristic codes included participants’ age, sex, relationship status, basic profile of drug use (ever use of traditional substances) and ever use of NPSs. Setting codes differentiated between samples (e.g. BYDS participants, those recruited from drug and alcohol services and those in prison). Setting codes also served to contextualise participants’ past and present environments and physical (e.g. growing up in care/varied familial structure), geographical (e.g. urban/rural and areas of social deprivation) and cultural (e.g. attitudes towards drug taking, normalised behaviour within peer and community setting) contexts.

After several checks and refinements, it was evident that in terms of ‘conceptual codes’ there was a range of factors driving groupings of certain respondents together. These broad groupings clearly dominated the data and affected how other subcodes and types of codes (e.g. relationship and perspective codes) operated in these groupings. After several team-wide assessments of the codes, we used them to construct a four-group taxonomy. A taxonomy is a system for classifying multifaceted, complex phenomena according to common conceptual domains and dimensions. A common language or taxonomy that distils complex information about groups of individuals into key components is paramount.

Our taxonomy identified key domains that were broad in nature. These included broad-based risk and protective factors at individual, family and community levels (guided also by quantitative analysis), detailed substance use repertoire and location of NPS in that context, patterns of use, primary motivations for substances used and critical incidents that resulted in either desistance or increased use. These conceptual codes defined key domains that characterised, for example, how the phenomenon of use in a ‘limited experimental’ way/‘contemporary regular’ way took shape, and differentiated them from one another. Conceptual subcodes helped to further define common dimensions in those key domains. One example was age as it interacted with market trends and availability; younger participants obviously reported greater exposure and access to NPSs during adolescence (with some initiating with NPSs), whereas older participants recounted early experiences with traditional drugs.

Key domains were also examined alongside multiple code types. For example, participant perspective was explored in conjunction with reported risk and protective factors from early years to present day (participant characteristics and setting codes) and relationships between exposure to risk, perception of risk and patterns of drug use/risk behaviour were noted. Participant perspective codes were also used, in terms of pleasure seeking as linked with certain taxonomy grouping (i.e. past recreationals and contemporary regulars). Furthermore, although persisters viewed severe intoxication from SCs as a positive side effect, contemporary regulars perceived these effects as highly negative.

Bradley et al. 85 noted that within each dimension there may be further subdimensions depending on the complexity of the inquiry. In our case, this meant further subdividing group 4, as detailed below. In essence, our taxonomy set out to describe a discrete set of axes or domains that characterised the multifaceted phenomena of NPS use. This was based on a conceptualisation that, over and above repertoire of drugs used, sex and so on, there was an overriding conceptual basis to why these taxonomy groupings were distinctive.

Intersectional analyses with data coded for participant characteristics and setting codes facilitated our comparative analyses as we finalised our coding framework. Biographical information on participants was reinforced by the use of our quantitative and qualitative data.

In the current study, we were keen to avoid simply pasting together data of two types; rather, we aimed to devise a system of data collection and analysis that followed a certain methodological logic, and one that met theoretical requirements, as dictated by the BYDS analysis, as outlined in Figure 1. A comparison of preliminary and emergent codes was back-coded to early transcripts to ensure coding consistency. This process was of considerable duration and the coding structure was considered finalised only at the point of theoretical saturation. 86–88 This is the point at which no new concepts emerge from reviewing of successive data from participants. Theoretical saturation took time to accomplish owing to diversity in our sample in terms of participant characteristics, perspectives and settings. Interviews ceased only when we were confident that data represented various NPSs from the perspective of the individual and reflected the multifaceted role that certain NPSs, and other substances, played in participants’ lives at different points in time.

The finalised code structure was then applied to the data delineated by taxonomy group and this approach (i.e. the five types of code) allowed us to generate themes by which to further analyse and facilitate theory development. The team met as a group to review any discrepancies (quantitative and qualitative) and resolved minor differences by negotiated consensus.

Themes evolved not only from the conceptual codes and subcodes, as in the case of our taxonomy group, but also from the relationship codes, which tagged data that linked concepts to each other. We recorded such linkages carefully within NVivo. We were able to conduct a comparative analysis of concepts coded in different taxonomy groups that were related to some extent by our basic setting codes. Through this comparison we attempted to assess whether or not certain concepts, relationships among concepts, or positive/negative perspectives were more apparent (as noted in the examples above) or were experienced/reported differently between taxonomy groups. This is evident in Chapters 3–7, where there is some exploration of setting codes, notably those in homeless accommodation or in prison settings.

Theory emphasises the nature of correlative or causal relationships and is used to explain phenomena. 89 We both deductively and inductively used theory within our study. For example, in our data, early-onset substance use was not linked to polydrug use trajectories after controlling for other influential variables. We attempted to be highly consistent in cataloguing relationships among concepts, using the constant comparison method to generate inductively conceptual codes and subcodes as well as relationship codes. Through its theoretical development, our study confirms much existing theoretical and empirical research but also suggests some new paradigms for understanding NPS as a deconstructed phenomenon.

Quantitative procedures

Ethics and governance

Ethics approval for the quantitative component of the study (i.e. secondary analysis of BYDS data) was granted by the Research Ethics Committee, School of Social Sciences, Education and Social Work, QUB, in November 2015. Approval for the qualitative component with non-BYDS participants was granted from the Office for Research Ethics Committees Northern Ireland (ORECNI) in December 2015. Owing to using health and social care premises as participant identification centres, global governance was applied for and attained in March 2016. The extension for the study to include the three prisons in Northern Ireland as recruitment sites was approved by the NIHR in August 2016. Ethics approval and governance as well as security clearance were all in place by March 2017.

Quality control and qualitative research

The inclusion of the BYDS sample as well as a range of recruitment sites reduced selection bias inherent to recruitment from clinic populations alone. A purposive sampling strategy allowed for the inclusion of outliers and discovery of deviant cases. Data were then interrogated on the basis of corroboration while paying attention to negative cases. Secondary analysis of BYDS data, coupled with the collection and analysis of empirical data, allowed for triangulation in terms of answering the research questions.

Interview data were first coded by the same two researchers responsible for conducting the interviews, thus ensuring familiarity with the data and maximising efficiency in terms of time and cost. Both researchers read and independently coded the first five interviews using the coding framework generated from the research questions, adding new codes where necessary. Following independent coding, the two researchers collectively discussed and agreed decision-making around codes. Coding was then discussed among the wider team, as noted previously, and the coding frame was developed with continuous cross-checking of data among the researchers and the wider team, facilitating refinement throughout analysis and prior to interrogation of data during interpretation.

The involvement of the wider team in discussions around coding, refinement and development of themes ensured that the two researchers responsible for conducting the interviews and coding data were not hindered by familiarity and proximity to the data.

Detailed memo-keeping, from data collection through to interpretation, provided a visual audit trail of thought processes as the study progressed and facilitated researcher reflexivity.

Reflexivity emerges from the position that social researchers are part of the world they study90 and relates to the ways in which data might be shaped by researchers and the research process. The majority of the interviews were conducted by two female members of the research team. Both researchers were white, heterosexual, aged 30–35 years, had backgrounds in academia and had experience of working in the area of drug use and with vulnerable populations in non-clinical settings. At the beginning of each interview, researchers took time to offer refreshments and informally talk to participants in an attempt to put them at ease. The researchers introduced themselves and talked briefly about their job and research interests. Participants were given the opportunity to ask questions and raise any concerns about the interview. Post-interview feedback indicated that almost all participants reflected positively on the interview, stating that they felt comfortable and that researchers were non-judgemental about information divulged. In addition, younger participants mentioned that they expected the interview to be much more formal, but the fact that the researchers were informally dressed, friendly and relatively young put them at ease.

There were initial concerns that the presence of two researchers during each interview might tip the power balance and result in participants’ discomfort or unwillingness to open up. This was mitigated by ensuring that one researcher led the interview while the other asked questions only intermittently and on invitation from the lead interviewer so as not to disrupt the flow of the interview. Furthermore, two researchers present at each interview was beneficial to the data collection process for a number of reasons: first, in terms of rigour, having two people conduct the interview ensured exhaustive probing of the participant narrative (i.e. no relevant information was missed during the interview); second, in terms of researcher safety on campus, at community venues and in prisons; third, in terms of emotionality – biographical accounts regularly included sensitive information on adverse life experiences, for example abuse (physical, sexual, domestic), loss of family members/friends and experiences of homelessness. On occasion, participants became emotional during their narrative interview; for some this was the first time they had recounted these experiences. In a similar vein, emotionality was an issue for the researchers listening to an individual’s story. Researchers were very much in tune with how the other was dealing with the interview, and were on standby to take over questioning if necessary.

In terms of the research environment, interviews were conducted in a range of settings, including a private office on university premises, private offices in community centres (for participants that did not reside local to the university) and private rooms at each of the prison sites. The potential for the physical setting to have an impact on the data is acknowledged in each space. The university, as an institution, may have been perceived by some as oppressive, despite our intent and efforts to make participants feel as comfortable and at ease as possible. During the informal chat with participants (after the recording device was switched off), no participant expressed concerns about the interview venue. Community centres were generally chosen by participants for ease of access and so posed few issues in terms of interview dynamic and physical space. The prisons as venues for data collection might be considered to be the most problematic venues. One might imagine that prison itself is an oppressive environment wherein issues around substance use could not be discussed freely. A pilot interview was conducted in the prison prior to data collection. Following the interview, the participant was asked about his experience and his opinion on the content of the interview. Researchers received positive feedback and the participant highlighted that the prisoner development unit, where interviews were taking place, was a regular venue for individuals to work with the AD:EPT team and other teams in the prison, therefore discussing substance use in this environment was not an issue.

The strengths and limitations of the study are discussed in Chapter 8.

Latent class analysis of the Belfast Youth Development Study

Determining the number of drug classes

This study was a secondary analysis of data from the BYDS, a longitudinal study of substance use during adolescence (see Chapter 1 for more information). The data extraction plan was prepared and confirmed between October 2015 and November 2015 and then finalised in December 2015 through consultation with the knowledge exchange (KE) group. A draft analysis plan that addressed each of the research components was negotiated and completed by the team in January 2016 and a number of strategies were implemented over the next month to prepare the groundwork and data for the first stage of the analytical plan. We hypothesised in our application and follow-up responses that a number of homogeneous subpopulations would emerge in the data and would include a class of NPS users given the adequate numbers of NPS use in the sample. As depicted in Figure 2, the first stage of this strategy was to apply LCA to the data to identify the number and nature of classes based on ‘ever use’ of the drug variables included in our data. These included alcohol, tobacco, cannabis, ecstasy, speed, LSD, cocaine, heroin, other pills, poppers and NPSs. The actual questions used to assess drug-taking behaviour are shown in Appendix 2, Table 13.

FIGURE 2.

Representation of basic latent class structure: traditional and NPS drug use.

As is standard in LCA, models with two to six classes were estimated using MLR. 91 To help prevent solutions based on local maxima and reduce the risk of missing the model with the best fit, initially 100 random sets of starting values were specified, with 20 final-stage optimisations. The models were then compared in terms of relative fit by using information theory-based fit statistics (Table 1), namely the AIC, BIC and ssaBIC. For these three fit measures, lower values are representative of better model fit.

TABLE 1 - Fit statistics for the models with one to six classes

BS-LRT, bootstrap likelihood ratio test; N/A, not applicable.

Number of classes	Log-likelihood	Best H0 replicated	Number of parameters	AIC	BIC	ssaBIC	LMR (p-value)	BS-LRT (p-value)	Entropy
1	–7793.80	N/A	11	15,609.59	15,671.41	15,636.46	N/A	N/A	N/A
2	–6039.21	Yes	23	12,124.41	12,253.68	12,180.60	3471.22 (< 0.001)	3509.18 (< 0.001)	0.89
3	–5674.01	Yes	35	11,418.02	11,614.72	11,503.53	722.49 (< 0.001)	730.39 (< 0.001)	0.83
4	–5612.82	Yes	47	11,319.64	11,583.79	11,434.47	121.05 (< 0.001)	122.37 (< 0.001)	0.77
5	–5588.16	Yes	59	11,294.32	11,625.91	11,438.46	48.79 (0.010)	49.33 (< 0.001)	0.74
6	–5576.52	Yes	71	11,295.03	11,694.07	11,468.49	23.04 (0.169)	23.29 (0.143)	0.76

The LMR and bootstrap likelihood ratio test were also used to compare models with increasing numbers of latent classes. Model estimates for both three- and four-class models were examined and the four-class solution was subsequently selected based on the interpretability of the results. After extensive exploratory modelling work we were able to determine that a four-class model was the best-fitting model according to the fit indices and information criteria; this provided us with unique and interpretable clusters of individuals with similar profiles within the latent SGs. Average latent class probabilities for most likely latent class membership are shown in Appendix 3, Table 14. Figure 3 shows that a four-class solution provides good cluster delineation (see Appendix 3, Table 15).

FIGURE 3.

Probability of substance use in each of the four latent classes identified in the BYDS data.

Therefore, a four-class solution was adopted in the present research to account for the different typologies of drug taking. The four classes of drug use identified were as follows:

1. Alcohol – high probability of alcohol use; a p-value of < 0.5 for all other substance use types.

2. AT – high probability of AT use; a p-value of < 0.5 for all other substance use types.

3. ATC – high probability of ATC use; average probability (p < 0.5) for all other substance use types. The probability of poppers (p = 0.44) and cocaine (p = 0.43) use, although a p-value of < 0.50, is noteworthy for this group.

4. Polydrug – high probability of alcohol, tobacco, cannabis, ecstasy, speed, cocaine, poppers and NPS use. Probability of a p-value of < 0.5 for all other substance types.

The percentage of participants reporting ever using drugs is shown by latent class in Table 2. The latent class probabilities for each substance type are shown by latent class in Appendix 3, Table 15. The sample sizes of the four latent classes were as follows: class 1 (alcohol; n = 532), class 2 (AT; n = 926), class 3 (ATC; n = 367) and class 4 (polydrug; n = 214).

TABLE 2 - Percentage of participants reporting having ever used drugs by latent class and substance type

Class	Percentage of participants
	Tobacco	Alcohol	Cannabis	Ecstasy	Speed	LSD	Cocaine	Heroin	Other pills	Poppers	NPS
1 (alcohol)	0.9	87.5	0.0	0.4	0.4	0.0	0.8	0.0	0.0	1.4	0.4
2 (AT)	97.1	100.0	42.0	1.4	0.3	0.0	0.4	0.0	0.0	3.4	1.0
3 (ATC)	98.6	100.0	97.8	37.7	9.7	1.4	43.5	0.3	5.6	53.2	16.9
4 (polydrug)	95.3	100.0	97.6	97.6	81.3	29.4	97.6	1.0	37.5	78.4	70.7

Informing the qualitative analysis

The aim of the qualitative component was to explore in detail the life experiences of drug users and, in particular, how NPS use related to their overall drug portfolio. If a unique NPS-only class had emerged from the LCA, the aim could have been achieved by sampling from this class. However, because this class did not emerge, an alternative sampling strategy was devised to examine NPS use qualitatively with adequate control for polydrug use. Sampling from only polydrug users would have made it difficult to distinguish between factors related to NPS use and those related to polydrug use. As shown in Table 2 and Appendix 3, Table 15, not all members of the polydrug group were NPS users. Therefore, in the qualitative analysis sampling, polydrug users were split into those who reported NPS use and those who did not. A small proportion of the class 3 (ATC) users reported using NPSs (see Table 2 and Appendix 3, Table 15). We wanted to explore this rare group of users further to shed light on why users who are more selective about substance use choose to try NPSs. Importantly, although the majority of ATC users did not use NPSs, the vast majority did report using cannabis. To distinguish between life experiences related to cannabis and to NPSs, individuals who reported using cannabis but not NPSs were also sampled from to serve as a comparator group.

In summary, to distinguish between factors related to NPS use and other drug use, sampling was based on four groups (Figure 4). Polydrug users were split into those who used NPSs and those who did not (polydrug and NPS users; polydrug users, no NPS). The ATC group (ATC and NPS users) were also sampled from, and a control group was formed of cannabis users who did not use NPSs (ATC no NPS). This allowed a distinction to be made in the analysis between NPS-specific experiences and those associated with cannabis. The specific criteria used to form the groups were as follows:

1. polydrug users and NPS – responded ‘yes’ to using mephedrone or legal highs; responded ‘yes’ to using all of the following: cigarettes, alcohol, cannabis, ecstasy, poppers and cocaine

2. polydrug users, no NPS – responded ‘yes’ to using cigarettes, alcohol, cannabis, ecstasy, poppers and cocaine

3. ATC and NPS – used mephedrone or legal highs, used cannabis; did not meet criteria for polydrug and NPSs

4. ATC user, no NPS – did not use mephedrone or legal highs, used cannabis; did not meet criteria for polydrug and no NPSs.

FIGURE 4.

Sampling strategy for the qualitative analysis.

Qualitative interviews with BYDS participants commenced using the sampling framework derived from the LCAs. As regression analyses ran concurrent to data collection, emerging significant variables in the multinomial logistic regressions were passed to the researchers conducting the interviews for additional probing, in case the themes emerged in the participant’s narrative.

Belfast Youth Development Study participants were selected and invited for interview based on the LCA and sampling framework presented in Figure 4. The qualitative sample was supplemented with individuals recruited from (1) drug and alcohol services and (2) the prison estates (see Chapter 2 for further information). Demographic information on the recruitment groups is shown in Table 3.

Based on the narrative data, and utilising our specific coding framework, we constructed a taxonomy of users (Table 4; see Chapter 2 for detail on construction). This allowed us to draw together the multiple lines of investigation. The rationale was that such data-driven classification would help us to identify subsets of participants.

Following the development of the taxonomy groups, the data were interrogated using text searches and matrix code queries. This process of interrogation was to explore shared/differing characteristics in and across group taxonomies.

Group 4 (dependents) was by far the largest group and had variability, which from both a theoretical and empirical perspective necessitated subdivision into SGs.

The narratives provided dynamic data on the life cycle of participants’ use. For those who abstained from use or had never reported NPS use, data on motivations to resist/desist were also included. Table 5 provides detail on interview participants by group.

As noted in Chapter 2, risk and protective factors were used as a shared theoretical lens between the quantitative and narrative data. To recap, longitudinal and other studies have identified a number of well-established individual, family, school and community risk factors that are associated with alcohol and drug use throughout the life course (see Chapter 2). 69–73 The overall larger BYDS research programme quantitatively examined these interactions in depth for a large number of respondents. 73 We do not lay claim to offering the same here. Rather, from a qualitative perspective the narratives articulate what these risks and protective factors looked like through the lived experiences of this group of participants. These are presented alongside information on the drug repertoires of the taxonomy groups (see Appendix 4 for detailed information).

Group 1: limited experimentals

Group 2: past recreationals

Group 3: contemporary regulars

Group 4: dependents

The dependents group, consisting of 52 participants, formed the largest group in our taxonomy. Dependents included individuals who self-reported dependency on one or more substance at some stage of their drug career. It is important to note that this was based on self-report of dependency and not verified independently by treatment data. However, in all narratives features of dependent use, for example in terms of tolerance and withdrawal, were noted.

The literature of drug dependency clearly evidences a sex disparity112 as well as reasons why females are less likely to report dependence. 113 We posit that female users were likely under-represented in this grouping and we are cognisant of the accumulating epidemiological clinical and qualitative research that suggests that what determines whether or not drug abuse and dependence develops or progresses further is often sex specific or sex sensitive. 112

Generally, the dependents group is characterised by having participants with more chaotic lives. Almost all were not in a relationship at the time of interview. The average age for substance use initiation was the earliest of the four groups, at 12.9 years (range 8–16 years). The majority initiated with alcohol (n = 36) and six participants initiated with cannabis. For a minority of the group it was not clear from their narratives which substance was used first; six participants reported synchronous onset with multiple substances, for example alcohol and cannabis, one participant reported using alcohol and mephedrone at the same age, one reported using alcohol and SCs at the same age, one reported using alcohol and ecstasy at the same age and one reported using cannabis and prescription medication at the same age.

Although all participants in the dependents group reported issues with dependency at some stage or another, patterns and levels of use within this group varied greatly. Some of the more established users reported long histories of drug use with multiple dependencies at various stages, whereas other, younger participants in this group reported dependency on a single substance [e.g. SCs, ‘synthetic’ acid/2,5-dimethoxy-4-iodophenethylamine (2C-I)]. Although all participants reported dependency, they were at very different points in their drug use career. Twenty-nine participants reported dependency on a single substance and 18 participants reported problems with multiple substances. Four participants from the dependents group reported never having used NPSs.

Subgroups

Given the significant variation in the dependents group in terms of participants’ dependency and relationship with NPSs, the group was subcategorised. SG1 comprised those for whom NPSs were their primary and only dependency. SG2 comprised those with dependency on a traditional illicit substance and for whom NPS served only to temporarily displace/substitute the traditional illicit substance (i.e. no dependency reported on NPSs). SG3 comprised individuals with multiple reported dependencies including dependency on NPSs.

Subgroup 1: generation new psychoactive substances

Drug repertoire

For SG1 (n = 14) the average age at initiation with any substance was 13.4 (range 11–16) years, with seven participants reporting alcohol as their first drug and two reporting cannabis as their first drug. For the other five participants it was not clear from their narrative which substance was used first; three reported using alcohol and cannabis at the same age, one reported using alcohol and mephedrone at the same age and one reported using alcohol and SCs at the same age.

Participants in group 4 were categorised into SG1 if their primary and only dependency was NPSs. The majority of the group (12/14 participants) had used SCs, with 11 participants reporting dependency on SCs. Five participants reported the use of mephedrone, with two reporting dependency. Three participants reported the use of other NPS powders, three reported the use of synthetic ecstasy (referred to as ‘herbal pills’) and one reported the use of NPS hallucinogens (e.g. 2C-I, 2C). The participant who mentioned using 2C, 2C-I reported dependency. For details of other substances, see Appendix 4.

Risk factors

When examining common characteristics of this group, peers stood out as the most common influential factor in terms of substance use, including NPS use. All participants reported that their friends used NPSs at the time of initiation. Watching friends and/or family using prior to first experience with NPSs served as a risk factor in this group. Community influences, including comments such as ‘everybody’s taking it’, and infiltration of NPSs into areas where young people lived and at sites where young people congregated were significant risk factors. Evidently the point in time at which NPSs emerged on the scene was significant given the age of participants in this group and the desire to experiment with substances. Notably, a proportion of participants in this group reported use, specifically of SCs, moving from social use with peers to use alone, which was an indicator of quick acceleration from experimental/social use to a more dependent pattern. The lack of knowledge about NPSs and naivety around what substances they were taking was a risk factor for this group, reflected in interchangeable terminology (e.g. ‘herbal’, legal highs, trippy) and elements of confusion when describing what they were using. Some reported not realising the signs of growing dependence on NPSs until they experienced withdrawal (e.g. sweating, vomiting, not being able to sleep, ‘craving the high’).

Early negative experiences with the education system was a predominant, common characteristic of this group. Seven participants in this SG were expelled from school/attended an alternative education programme. The remainder reported disengagement with education, with two participants leaving higher education as a result of their NPS use. Seven participants reported using substances in their school environment. Just as lack of school attachment is associated with substance use,114 so too are the reactions of the schools and employers reported here by the generation NPS group. Excluded from school, these children were removed from a relatively pro-social environment, leaving them with more free time in which to engage in substance use behaviour. 115

Going to live with other family members (commonly a grandparent) or leaving home as a result of other family issues, for example parental alcohol use, parental mental health problems and conflict between teen and parent, were also common. Parental substance use can lead to child substance use: the child observes and then imitates their parent’s behaviour. 116 In addition, in households where parents are problem users, there tends to be less routine, more conflict and fewer feelings of warmth and caring,117 further increasing the risk of substance use problems for their children. Indeed, lack of a structured environment was evident in the narratives: some participants reflected on hiding use from parents, yet it was clear that a number of parents were aware of substance use behaviour and did not seem to intervene effectively, either ignoring the behaviour or offering advice but with no sign of discipline or monitoring/control of behaviour. Parents splitting and conflict between parents were also factors for a significant number in this group. Parental separation has been found to be a key risk factor for early substance use, even after controlling for environmental and genetic factors. 118 A small proportion reported using NPSs with a partner and two out of the three females in the sample highlighted male partners as facilitators of their use in terms of initiating substance use. Eight of the sample reported that NPSs functioned for them as a means to achieve escapism, help with anxiety/depression and a distortion of reality.

Protective factors

In contrast to groups 1 (limited experimentals), 2 (past recreationals) and 3 (contemporary regulars), discussion of any kind of protective influence was rare in the narratives of this generation NPS group. Being aware of deaths in the community, effects of their use on family members and peers stopping use were all factors highlighted by those who sought help with their dependency or ceased use by their own accord.

Subgroup 2: availers

Drug repertoire

Participants reported dependency on one or more traditional illicit substance and no dependency on NPSs. NPSs were ‘availed’ of by this group when their drug of choice was not obtainable; thus, NPSs only temporarily displaced traditional drugs, much like those in the contemporary regulars group. The average age at initiation in this SG was 12.6 (range 8–15) years. In total, 12 participants initiated with alcohol, two with cannabis and one with alcohol and cannabis at the same age. In terms of drug-taking profile, participants in SG2 resembled those in group 3 in terms of willingness to experiment with a range of drugs; however, SG2 differed in that participants reported use of heroin, which group 3 participants did not, and were more likely to report use of prescription medication.

Risk factors

The majority of participants in SG2 discussed mental health issues in the context of their drug narratives. Issues associated with mental health included depression, anxiety, panic disorder and schizophrenia. One-third of the group reported self-harm and suicide attempts. Of course, there is a much more complex interplay of factors regarding dual diagnosis, particularly in relation to the extent to which mental health problems contribute to substance use and the degree to which substance use exacerbates mental health problems. 119 All participants in this group used substances with peers and, for many, peers increased risk in terms of initial access to drugs. Half of the group reported excessive use of alcohol during their drug careers. Most of this group reported limited engagement with education (n = 11); this ranged from lack of interest in school to expulsion and removal from mainstream education (n = 5). The majority of this group reported contact with the CJS, with contact largely related to drug-related offences, including possession, supply, crime to fund use and crime committed while under the influence. This crime and substance use nexus is believed to further escalate both behaviours, leading to more persistent offending and greater substance dependence. 120

Protective factors

This group was interesting in that almost half of the participants (n = 7) described the influence of parents as largely protective and many of them questioned their motivations for drug use and the trajectory of dependency that followed, although, given the multitude of risk factors identified in their narratives, it is perhaps unsurprising that this protective influence was not enough on its own to limit or prevent their substance use dependency. Some attributed decision-making around drug use to factors associated with personality, for example impulsivity and desire to take risks. However, most of those who reported stable upbringings also acknowledged that they self-medicated to cope with their mental health issues and/or reported experiencing the death of a close family member or friend during teenage years. Almost one-third of SG2 participants discussed employment in a protective capacity and, for those outside prison, they seemed, like contemporary regular group participants, to measure functionality in terms of not missing days at work as a result of substance use.

Subgroup 3: persisters

Drug repertoire

The persisters SG includes the most chronic substance users (n = 18). All participants in SG3 reported multiple dependencies, including dependency on NPSs. The average age at initiation in this group was 11.7 (range 10–16) years. A total of 12 initiated with alcohol, three with cannabis, two with alcohol and cannabis at the same age, one with alcohol and ecstasy at the same age and one with cannabis and prescription medicines at the same age.

Participants in this SG, as with those in SG1, initially believed that SCs offered a safer alternative to the traditional illicit drugs that they were using in a harmful way. Comorbidities and vulnerabilities among this group made the potent effects of SCs particularly appealing and so resulted in sustained use. This SG was particularly well placed to track the evolution of SCs over time. Ironically, legislation designed to reduce the harm of SCs was counterproductive and resulted in the development of more potent and particularly risky third-generation legal highs.

Risk factors

Almost all documented risk factors were at play for this group and included negative experiences at school, adverse life/childhood experiences, mental illness, contact with the CJS, complex family issues, social deprivation and homelessness. In terms of education, 17 participants in this group reported significant disengagement with education, including being expelled (n = 12). One anomaly was a male participant from our service-using sample who attended school (and is now at university) but reported problems throughout school as the school environment exacerbated his underlying anxiety problem leading to more excessive substance use at that age.

A large proportion of participants in this SG reported an unstable home environment while growing up. Ten participants reported that one or both parents used substances themselves and in three cases a parent was instrumental in facilitating substance use (selling, providing substances). There was clear evidence of a lack of parental monitoring owing to parental substance use and issues such as strained relationships in the home or other adverse experiences relating to family life. More than half of the participants in this SG disclosed adverse life/child experiences (e.g. around one-quarter mentioned physical or sexual abuse). Unfortunately, those who have experienced such abuse are more likely to suffer negative consequences from using drugs. 121 Five reported the death of a close family member and two reported the death of close friends.

Generally, having children was not a protective factor for this SG. Four participants had lost contact with their children/had children removed by social services, one of whom was regaining contact with his sons who are now adults. For the other three participants in this SG, substance use ceased/decreased during pregnancy/early years, but participants later resumed previous patterns of use.

For almost half of the participants in this SG, mental illness (anxiety, depression) was reported. Evidence of self-medication, in most cases through the use of SCs, was particularly highlighted by participants who had had adverse experiences or periods of homelessness.

As one might expect, all participants in this SG had contact with services at some stage. Five participants had contact with social services; for two this spanned more than two generations. Two participants reported being in care as a child. Consistent with the features of SG3, people who were in care as children tend to use drugs more regularly and use higher-class drugs than those who were not in care as children, making them a key group to monitor for substance use problems. 122,123

Seven participants in this group had experienced homelessness at some stage and three were residing in hostels at the time of interview. Homelessness did not emerge as a risk factor for any of the other groups or SGs and it is likely that the severity of SG3 participants’ drug dependency led to them losing their home and made it difficult to rehouse them; this may also have escalated their drug dependency, taking drugs in an effort to cope. 124,125

Contact with the CJS was common in this SG, with 15 participants reporting contact dating back to their early teens. Two of our female participants reported prostitution. There was evidence of contact with drug and alcohol services and multiple substance dependencies prior to NPS use for the majority of this SG.

Protective factors

The narratives of SG3 participants included references to risk factors; any kind of protective influence was lacking. For five participants in this SG, children were initially described as protective influences. These respondents reported abstaining from drugs when their children were born; however, the breakdown of relationships with significant others, or the removal of children from care, precipitated relapse. Nine participants described rebuffed efforts of family and friends to intervene and offer help and support. Several respondents reported creative, if unsuccessful, efforts by family and friends to assist in drawing attention to the effects of NPSs when participants were under the influence; for example, some participants were video recorded and the footage was shown to them when the participant was sober in a bid to deter them from future use. Employment was highlighted as protective for some in terms of either abstaining or reducing use, and job loss was described as a risk factor for relapse or returning to heavier drug use. Four of those from the prison sample highlighted prison itself as a protective influence and expressed concerns that they would return to using drugs on release.

Subgroup 4

Subgroup 4 did not report any use of NPSs while being dependent on other substances. They indicated that other substances were preferable and they chose not to use NPSs. The data on this group were very limited. Although this group was retained for transparency in the analysis, they are not reported on in detail.

Figure 5 summarises the risk and protective factors that emerged from the narratives by SG.

FIGURE 5.

Groups by repertoire and risk/protective factors. a, In comparison with other SGs in group 4.

Chapter summary

The LCA revealed that only one class of substance use [class 4 (polydrug)] was characterised by NPS use. The multinomial regressions (see Appendix 5, Tables 18–20) showed that, based on the relative magnitude of effect sizes and number of significant differences between polydrug users and the other groups, there is a clear relationship between number of substances used and cumulative exposure to risk factors. In terms of exposure to drug-taking risk factors, polydrug users had the highest levels of exposure, followed by ATC users, then AT users, with the alcohol users showing the lowest levels of exposure.

The four-group taxonomy detailed patterns of substance use throughout our qualitative sample, ranging from those with very limited drug use repertoires to those reporting chronic use and dependency. Our data confirm the increasingly numerous messages from the literature that NPSs are best conceptualised as having a place within a polydrug use trajectory. As noted, commensurate with this hypothesis, our LCA did not generate a distinct NPS group, nor did it map neatly onto our qualitative group classifications. Rather, different NPSs made their way for different reasons and to different extents into the taxonomy groups 2–4.

Consistent with existing literature on trajectories of drug use, the taxonomy groups derived from the narratives clearly evidenced incrementally less favourable outcomes and multiple risks and adverse incidents as we progressed from group 1 to group 4. Common risks were early age at onset of substance use and length of substance use career. For example, age at onset progressively reduced as we moved through the taxonomy. The limited experimentals’ mean age at onset was 15.6 years, the past recreationals’ was 14 years, the contemporary regulars’ was 13 years and the dependents’ was 12.1 years. In addition, current and past extensiveness of substance behaviours appeared closely linked to early-life difficulties as reflected in the narratives (e.g. problems at school and the presence of criminal involvement in youth).

Dynamic changes such as important life events or ‘turning points’126 that can serve to protect or mitigate risks also showed a decreasing gradient as we moved through groups numerically. That is, such protective influences diminished rapidly by group to the extent that group 4 participants had few protective factors noted. Marriage, functional romantic relationships and a desire for financial security featured much more strongly in the narratives of the first two groups. Relationship breakdown, childhood in care, relapse or remission of physical and/or mental illness and bereavement appeared to have a firm influence on a person’s trajectory. The relative impact of these can be seen when looking across the four trajectories. Similarly clear was the cumulative effect of exposure to multiple adversity, which was very apparent in the female participants, especially the seven who fell into the dependent group. This summary of our groups through the narratives builds a picture of how risk factors were inter-related and tended to cluster together. For example, adverse childhood experiences appeared to be related to other family-level risk factors, for example poor parenting skills and parental substance use and mental illness.

A growing number of researchers are critical of too heavy a focus on risks at the expense of describing the specific pleasure and functions of specific drugs. 127,128 Whereas this chapter has focused on risk, the pursuit of pleasure as it relates to NPS use of varying types is discussed in Chapter 5.

Risk factors associated with drug class membership

As reported in Chapter 3, 16 themes associated with more-problematic substance use were identified (Figure 6). The first 15 themes emerged directly from the qualitative analysis. When these themes were presented to the PAG for feedback, the group felt that these themes were in keeping with their professional experience. The PAG also felt that, based on their experiences of working with substance users, personality was often a key factor linked to problematic drug use. The qualitative transcripts were subsequently revisited, and the team concluded that these supported the PAG suggestion that personality is a key theme; specifically, impulsivity tended to characterise more problematic drug users.

FIGURE 6.

Themes associated with greater drug use dependency.

In keeping with the quantitative–qualitative–quantitative design of the research, in the third stage of the research quantitative modelling was used to assess the generalisability and relative importance of these themes using the quantitative BYDS data.

Selection of longitudinal risk factors based on the qualitative narratives

To assess if the identified themes were associated with more problematic drug/NPS use, BYDS variables were mapped onto these themes. The BYDS variables were then used to predict the latent classes identified in Chapter 3. The process of mapping BYDS variables to the themes is illustrated in Figure 7.

FIGURE 7.

Flow chart of the process of aligning BYDS variables with themes.

As Figure 7 shows, first the qualitative researchers briefed the project team on the 16 themes identified and their meaning, and the other team members asked follow-up questions to clarify the meaning of each theme.

Subsequently, the quantitative researcher reviewed the BYDS data sets to identify potential matches between BYDS variables and the risk factor themes. This review process involved searching the BYDS data files with key match terms, reading through the BYDS questionnaires, reviewing BYDS coverage documentation (for example, scales included in BYDS) and using project team knowledge of the data sets from previous BYDS analyses.

The variables identified were summarised in a document that was then discussed with the project team. The discussion highlighted that many of the variables fit well; however, for some themes the fit was less precise. Some variables were initially identified but excluded after discussion with the team because of poor fit (see Report Supplementary Material 3, Table 51). The qualitative researchers felt that these variables should be excluded because they were not representative of the detailed narratives from which the themes arose. Where poor fit to a theme occurred, further clarification was provided on the nature of the themes by the qualitative researchers and the review process of BYDS variables was repeated for those themes.

Several cycles of mapping the BYDS variables to the themes and cross-checking alignment with the team continued until the team was confident that it had maximised alignment between the BYDS variables and themes. The final set of BYDS variables identified as suitable predictors of problematic drug use are shown in Report Supplementary Material 3, Table 51.

The variables included and excluded via the matching process are as follows:

1. 1. Leaving home early. In the BYDS data sets there was an indicator of who the participant currently lived with at waves 6 and 7. The measure at wave 6 (participants aged 16–17 years) was deemed more suitable because by wave 7 (age 21) it would not be unusual to live away from parents.

2. 2. Problems at school/lack of enjoyment. From the range of school-related measures in the BYDS data sets, problems with ‘school commitment’, ‘school attachment’ and ‘being bullied’ were considered to be most reflective of this theme. Measures of school commitment and school attachment from waves 1 to 5 were available; however, only waves 2 to 5 were selected for inclusion in the present study as the response options at wave 1 were different.

3. 3. Leaving school early. In wave 7 BYDS participants were asked at what age they finished school. However, it was impossible to tell if those who left at age 16 years had disengaged with education. For example, some may have gone on to study for Advanced level (A level) qualifications or National Vocational Qualifications (NVQs) at further education colleges. Indeed, many of those who reported leaving school at age 16 years reported getting A level qualifications. As participants were not specifically asked if they attended a further education college at age > 16 years it was decided that the BYDS data could not be used to derive an indicator of leaving school early. Having failed to obtain six or more General Certificates of Secondary Education (GCSEs) at A–C level (‘≥ 6 GCSEs’) was chosen as a suitable proxy indicator for early disengagement from school.

4. 4, 5 and 14. Parental substance use, family breakdown/parents splitting and family mental health problems. Several themes related to family dysfunction emerged from the narratives, namely family breakdown, parental substance use and family mental health problems. Family breakdown, in the context of the narratives, refers to one or both parents moving out of the household. The BYDS participants were asked who they lived with at each wave while they were in compulsory post-primary education. A measure indicating if parents had moved out the house was computed from this (‘natural parent moved out’). Although living arrangements data are held for waves 1 to 5, it was decided to base this variable on change between waves 2 and 5; this was because of high levels of missingness for this variable at wave 1 (partly because some schools had not joined the sample by wave 1). The full BYDS data set did not hold measures of parental substance use and family mental health problems. There were some measures in the BYDS family survey, such as parental alcohol and cannabis use. However, the family survey only covered a small proportion of the BYDS full sample, making these variables unsuitable for the present analysis. Instead, two measures of family dysfunction were selected to closely align with these themes. The first was a measure of parental control129 and the second indicated if parents allowed their children to drink alcohol (‘unsupervised alcohol’). Unsupervised alcohol use was based on the wave 4 measure; prior to and after wave 4, unsupervised alcohol use was either very uncommon or very common. Parental monitoring129 and the inventory of parent and peer attachment130 were also considered as measures of these themes, but were considered not to align closely enough with the narratives.

5. 6. Bereavement/loss/grief/abuse. BYDS contains several questions relating to online abuse. Surprisingly, online abuse did not arise as a theme in the narratives; rather, the abuse described by participants was face to face in nature. Physical abuse was measured by BYDS at waves 5, 6 and 7; for example, participants were asked if they had been a victim of a violent crime involving force or threat in the last 12 months. However, because the physical abuse questions related to the last 12 months as opposed to ‘ever’, this meant that coverage of physical abuse would have been too patchy to allow the compiling of a useful measure. At wave 5, participants were asked if they had lost one or both of their parents; this was selected as a measure of theme 6 (‘Death of parent/s’).

6. 7. Contact with the CJS. Initially, BYDS questions such as ‘have you ever been in trouble with the police?’, ‘have you ever been arrested by the police?’, ‘have you ever had a formal warning at a police station?’ and ‘have you ever been to court for anything you did?’ were highlighted. These were considered by the team to align with the narratives, and consequently a measure of contact with the CJS was formed from these measures. The team felt that further measures related to this theme were needed to reflect the detailed delinquency experiences captured in the narratives. After further discussion and searches of the BYDS variables, it was also decided to include measures relating to loitering such as ‘hanging around on the street or in the park’. In addition, a measure of ‘delinquency’ in adolescence was selected.

7. 8. Risks in terms of romantic partners and peers. Measures of peer and partner substance use in the BYDS data set cover a wide range of substances (e.g. cannabis, ecstasy, amphetamine and cocaine). The team felt that heroin did not feature in the narratives and therefore peer and partner heroin use was not considered to align with this theme. ‘Peer and partner cannabis, ecstasy/amphetamine and cocaine use’ was selected to represent this theme.

8. 9. Contact with drug and alcohol services. Two indicators of contact with drug and alcohol services were identified: ‘have you gone to anyone for help with a drug problem?’ and ‘have you ever been in a treatment programme specifically related to drug use?’. It was decided to construct an indicator of contact with drug and alcohol services based on answers to these questions.

9. 10 and 11. Sheltered accommodation and homelessness. The team chose not to include measures of these themes in the quantitative models as the narrative analysis revealed that this was more reflective of the service users’ part of the qualitative sample and less reflective of the BYDS participants in the qualitative sample.

10. 12. Children (not a protective factor). Interestingly, having children did not appear to serve as a protective factor against drug dependency. At wave 7, participants were asked if they had had children and this was selected to measure and assess the generalisability of this theme.

11. 13. Mental health problems. The BYDS data sets contain a wide range of mental health-related measures, including emotional subscales of the Strengths and Difficulties Questionnaire (SDQ);131 Moods and Feeling Questionnaire;132 Psychosis Screening Questionnaire (PSQ);133 self-harming behaviour and deliberate self-harm questions (derived from Hawton et al. 134) and the depressive symptoms scale. 135 It was decided that an early measure of mental health would be most suitable, ideally before the commencement of drug use problems that could have made mental health problems worse. In addition, as anxiety was highlighted as the main mental health issue emerging from the narratives, the selected scale needed to assess this. Subsequently, the emotional symptoms subscale at wave 1 was selected as the measure that most closely aligned to this theme.

12. 15. Early-onset alcohol and drug use. In each wave, BYDS participants were asked if they had ever used alcohol and if they had ever been drunk. In choosing between ‘ever used alcohol’ and ‘ever been drunk’, frequencies were considered. Even at age 12 years, a large proportion of BYDS participants had tried at least a sip of alcohol and therefore the team decided to focus on the ‘ever been drunk’ variable. Other studies were reviewed to determine what cut-off points are typically used to define early-onset alcohol use. Cut-off points ranging from age 12 to 15 years are reported in the literature. 136–144 Of course, these studies represent a range of different countries and consequently a range of drinking norms. Therefore, international comparisons of early alcohol intoxication by age 13 years were considered;145 in international comparisons the UK had the highest percentage (24%) of young people who reported being intoxicated by age 13 years, with the exception of Denmark. The team felt that based on this it would make sense to classify early-onset alcohol use as those reporting having ever been drunk by wave 1 of the study. Using similar logic, the team decided to classify the early onset of cannabis use as having tried cannabis by wave 2; frequencies revealed that cannabis use by wave 1 was uncommon.

13. 16. Personality. The BYDS data set included items from the International Personality Item Poll personality scales such as impulse control, emotional stability and risk taking. It was decided that impulse control was the personality dimension that emerged most strongly in the narratives.

The variables included and excluded as a result of the team discussions are summarised in Report Supplementary Material 2, Table 51. The coding of the included longitudinal predictor measures is detailed in Appendix 5.

Adult outcomes associated with drug class

The next stage of analysis involved looking at adult outcomes (participants aged 21 years) associated with prior life course drug history. The adult outcomes investigated covered key aspects of adult life such as mental health, education, employment, offending, contact with the CJS and substance use. The outcome models were designed to incorporate key findings from the qualitative analysis. Specifically, risk factors that emerged from the narratives and were significant in the predictors of latent class membership analysis were included in the models. This meant that factors associated with later drug use were controlled for in the models. The coding of the longitudinal measures is detailed in Appendix 5.

Legal status

Although NPSs have never been legal for sale in terms of human consumption, the initial legal status of some substances was an influential driver for use for several respondents in our study. Legality served as a motivating factor for different reasons among different groups and for some was deemed more important than other factors. Respondents were clearly literate regarding the legislative context of NPSs and discussed the availability of various NPSs alongside policy, for example the availability of mephedrone was often observed before and after the 2010 ban. Interestingly, discussion surrounding the perceived legality of NPSs was particularly notable in the narratives of three distinct groups (past recreationals, generation NPSs and persisters), all for different reasons.

Cultural and contextual setting codes proved immanent in relation to attitudes to NPSs among certain groups. For past recreationals, legality was discussed in the context of availability and normalisation as well as source of availability (e.g. obtaining substances from a headshop in comparison with a street dealer):

Just whenever it was legal it was easy to get, it was very easy to get, a lot easier and a lot less risk, significantly less risk than trying to find a drug dealer.

1001

Another participant reflected on the interplay between legality and availability but highlighted that legality was not the driving force behind motivation for use:

I think if [mephedrone] had of been available the way that it was and been cocaine I probably would have taken it anyway, but I don’t think it would have been as available if it hadn’t of been legal if you know what I mean . . . I think if you are going to take stuff like that you are going to take it whether it’s legal or illegal.

1012

Legal status proved a conduit for crossover between scenes; that is, mephedrone emerged in scenes previously characterised only by AT use:

It was ridiculous – people were handing out grams of [mephedrone] for nothing, do you know what I mean, it was just everywhere. People were – you know, mates were buying it off the internet just to have at parties. You know, like £100 worth – getting X amount of grams, and that was going to do a party whatever night. It was a really weird drug – there were people taking it who wouldn’t have ever taken [ecstasy] or anything else.

1036

The legal status of mephedrone was not mentioned by anyone in the contemporary regulars group as a motivating factor in terms of use; rather, it was discussed in the context of increased availability and accessibility. In these cases, legality was not highlighted as a driving force but something that facilitated ease of access; however, this did not deter use post ban. Use ceased when availability declined and the quality of NPSs deteriorated, coinciding with the improving quality of traditional substances.

Among dependents, perceived legality around NPSs was most resonant for generation NPS and persisters. Generation NPS discussed the legal repercussions of possessing substances and the source of availability with regard to NPSs versus traditional substances:

You see we used to get told that if you had the herbal the police don’t have to take it off you, so we were like, ah that’s handier. So we thought we could walk about the town and smoke herbal. If the police were to say anything, this is herbal. But still got lifted [arrested] for it. I never got lifted but a lot of my friends got lifted and brought home.

1053

Although most of generation NPS accessed the substances from both headshops and street dealers, some participants discussed the transition from mephedrone to SCs following the ban. In these instances, perceptions around legal status drove decisions to switch substances:

That’s when I realised that I was severely addicted to mephedrone – and the day it was made illegal was the same day that I stopped taking it, because I didn’t want to go and find it off an illegal dealer. But the day I stopped sniffing mephedrone, I started smoking this thing called ‘magic’, ‘black magic smooth’ or something.

1054

For the persisters, it was evident from setting codes that NPS use served as a means to bypass drug screens. This was the case for those in contact with services and, perhaps most notably, for those in prison:

It was a way of taking it and bypassing the drug test, where now they test for it now so you know, I mean obviously they can’t test for everything because of all the new strains that’s coming out, when they couldn’t test for legal highs that would have been the way people was going, it’s like when people were turning from cannabis to heroin because it was less likely to be tested, they were turning from cannabis or heroin to legal highs because they weren’t going to get caught.

HMP1004

I mean that ‘Sky High’ stuff, I just had a bad whole time with it, it wasn’t what I thought it would be, because I did smoke stuff called, some legal weed called ‘herbal haze’, that was OK, and it wasn’t showing up on drug tests so I didn’t care, I was still getting stoned, I wasn’t collapsing, I wasn’t showing on a drug test, but I suppose they can put anything into them psychoactive substances.

HMP1005

Availability and accessibility

Availability of NPSs was a theme that cut across all groups in the taxonomy and proved more influential among specific groups as a driver for use. Availability proved instrumental in terms of motivations to use for the past recreationals. Use of NPSs was opportunistic in the same way as use of traditional illicit substances. Decisions to use or not to use NPSs in this group centred around what was available and presented to them by peers during the time at which they experimented with drugs. When discussing non-use of NPSs, one participant stated:

When I was coming up it was more like recreational drugs that were available like ecstasy and cocaine.

1009

One participant from this group who had used mephedrone reflected with regret on her use but framed it in the context of a scene wherein use was common owing to legality and availability:

When mephedrone came in, that was legal and that became popular, it was everywhere, I remember that it was everywhere and everybody was using that because it was legal at the time and we all would have dabbled in that unfortunately.

1012

Factors that were key in terms of availability for those in the past recreationals and generation NPS were the availability of NPSs and the ease with which participants were able to obtain the substances in comparison with traditional drugs. One participant reflected on the experience of accessing NPSs while studying in England:

You could have gone to the headshops and got them. They were dearer than buying them off the internet themselves. You could just so easily get it. You were in town, you were drinking in pubs in Liverpool and it was Saturday at 4 o’clock, then one of the lads would be like, ‘right, I’m away to [headshop] for a bag’.

1037

No-one from the past recreationals group reported accessing mephedrone post ban, nor did they access NPSs through street dealers. Substances were either sourced through headshops or provided through social supply from peers. In these instances, legality clearly played a part in accessibility.

For most of the contemporary regulars, NPSs were not availed of in an opportunistic way. Rather, contemporary regulars’ narratives tended to focus on the interface between availability and quality, specifically the declining quality and availability of traditional drugs and the subsequent transition from illicit stimulant drugs to NPSs, primarily mephedrone, when it was available. For most in this group, quality was as much of a driving force as was availability:

The only reason mephedrone really came on the scene was because the ecstasy had died out so they were trying to get something to replicate the effects of ecstasy so the mephedrone was there and now the ecstasy has come back in, the ecstasy is booming again now because it’s really good.

1008

So I took Es [ecstasy pills] then for quite a while and then they sort of started to fade out like I remember they were getting dearer and harder to get and then like the quality of them was getting worse and then you were hearing more and more stories in the news about people like dying and bad batches and stuff going about. Then what did I move on to . . . I think then meph[edrone] came on the scene as far as I know, at the time I think it was legal, ya know when it first came round, and everyone was getting it off the internet and stuff like that, it was just easy to get and that was for a couple of years.

1018

In terms of source of availability, unlike the past recreationals, the contemporary regulars reported self-sourcing NPSs and accessed mephedrone from both headshops and street dealers. A number of participants also reported sourcing mephedrone post ban in 2010, reinforcing the fact that the legal status merely mediated accessibility as opposed to influencing decisions to use.

For the availers, NPSs filled the gap in a similar fashion. However, rather than NPSs temporarily displacing traditional illicit drugs, they were perceived as more of a substitute/contingency plan when participants were unable to access their traditional illicit drug of choice:

There was one called Smoke, something Gold, a few different things I can’t remember the names of them all now, so I would try them all and once or twice when I couldn’t get any hash I would go down to the headshop and buy them because I really missed having a smoke.

1027

So if I couldn’t get the real thing, I would get the China White, which sometimes that would be quite regular . . . And as far as those herbal highs and stuff like that, I never bother with them because I can always get cannabis if I want to, it’s not a problem, so I don’t really see the point in getting . . . to be honest with you, I haven’t even tried it and I’ve heard very negative reports about it.

1032

For generation NPS, availability of substances (particularly SCs and mephedrone), in conjunction with the point of their drug career (i.e. stage of experimentation), was crucial in terms of motivations for use. In terms of cultural setting, SC use was described as normalised, as cannabis use was for previous generations:

Herbal’s been about for a long time but it only really blew up last year. Last year was when it all blew up, everybody started using it.

1046

The impact of the legislative ban on availability of NPSs was a focus in the narratives of generation NPS:

It’s [SC is] everywhere, always, but it got banned so it’s harder to get now, it only got banned about 2 or 3 months ago.

1044

Potency and quality

The quality and potency of NPSs emerged as influential in terms of motivations for use and decision-making; these factors varied across the groups for different reasons. For our contemporary regulars, it was the quality of mephedrone and the time at which it emerged on the market that proved most significant.

Evidence (primarily seizure data) suggests that NPSs such as mephedrone emerged on the scene at a time when the quality of illicit party drugs such as MDMA and cocaine were at an all-time low. This perceived lower quality and continued demand for these types of drugs, coupled with the emergence of a substance that was cheaper, more widely available, not controlled under existing drug law and more potent, made for a perfect storm:

Whenever the meph[edrone] came on the scene big time that totally took away the cocaine, nobody wanted to buy coke. Why would you go and buy £40 of rubbish cocaine that basically does nothing to you and is probably 2 or 3 per cent purity whenever you could go and buy a bag of mephedrone at the start for £10? It was a full gram, like a gram could keep you rocking for hours, give you the real high like you were taking ecstasy.

1008

Our persisters also commented on the quality of mephedrone in comparison with traditional stimulant drugs, as well as stimulant NPSs that preceded mephedrone:

The way the drug scene went there, all these legal highs came on the scene because all the good say good drugs, all them illegal ones had been about for ages and everyone that was doing it just all disappeared off the scene, like the mephedrone and all came out because all the ecstasy disappeared so people were looking [for] something that’s close to it so then that came on the scene.

1059

The ‘Gocaine’ was just crap after that, once the mephedrone was there it was better, obviously it was a lot stronger, different hit, better hit.

1020

In terms of SCs, the case was somewhat different in that motivations to use were more associated with potency as opposed to a quality issue with traditional drugs, such as cannabis. The potency of SCs appealed specifically to those in our most vulnerable group (generation NPS) and our most chronic dependent users (the persisters) (see Chapter 7 for more information). Although initially taken by surprise by the effects of the SCs, the persisters nevertheless went on to treat SCs as an important drug of choice in their repertoire as it provided the total block many of them required. This was particularly noticeable in the homeless community or for prisoners in long-term lockdown. For generation NPS this potency had appeal for the younger vulnerable participants in terms of value for money and effect.

Among the contemporary regulars in particular, there was a sense of a very market-literate group. These participants focused heavily on policy and legality in terms of traditional substances, NPSs and decriminalisation and regulation. They appeared very aware of the relationship between legality, quality and availability, as evidenced by this respondent:

I see like in Holland if you ask them can you get mephedrone, you know like they can get you ecstasy, they can get you cocaine, they can get you anything you want, it’s all the best of quality, everything is top quality. If you ask them what mephedrone is they’re like ‘meph[edrone], what’s that, it’s rubbish, it’s crap, why, what is this?’. They never had to take mephedrone because their ecstasy has always been good . . . they’ve never had to experiment because they can go to their coffee shops, buy their cannabis and they can take their ecstasy, don’t need to be going down routes of mephedrone, these silly legal highs.

1008

Cost

In a general sense, throughout the narratives, mention was made of the low cost of various NPSs when they first emerged. This was particularly evident in the case of mephedrone following its emergence, but did extend to comments on SCs also. Cost of NPSs as motivation for use was discussed to some degree by participants in all groups; however, other factors emerged as more influential in terms of decisions to use or not to use NPSs. For example, a small number of students from the past recreationals group described the low cost of mephedrone as a driver of their use during a time in their lives of limited funds and experimentation. Group 3, who were contemporary users, also discussed cost, but more in the context of cost and quality of mephedrone relative to cocaine.

Cost (mostly of SCs) as a driver for use was most often observed in the generation NPS and persisters SGs. Among the generation NPS SG, the relative value for money in comparison with cannabis was highlighted:

The reason why people sort of switched to herbal is because you get ridiculous amounts for your money and . . . because of the stronger buzz.

1048

The initial appeal of perceived cost-effectiveness resulted in unintended consequences for some in terms of toxicity (explored further in Chapter 6):

I went in to try and get served but they wouldn’t serve me because I wasn’t 18. I got a wee guy to go in and get me it and he went in and got me it and came back out, 3 grams for £15. I thought, ‘****, you’re paying £20 for nearly 1.5 [grams] of grass‘. I thought, ‘this is cheaper in money and you’re getting double the quantity‘. I said, ‘sweet‘. I tried it and I woke up in hospital.

HMP1022

Cost was not static and was closely linked to other market forces. Generation NPS observed the way in which cost of SCs increased following the ban. When asked if SCs were cheaper than cannabis, one participant stated:

It was but it’s not anymore because it’s banned now. It used to be £20 for 7 grams, pure cheaper like and all you needed was one or two bongs.

1044

Among those in the persisters SG, cost also emerged as a key factor in terms of motivation to use. Similar to generation NPS, participants in this SG compared NPSs (primarily SCs and mephedrone) with traditional drugs and opted for the most cost-effective option (lower cost + greater effect = preference for NPSs/SCs):

At that time I was like, ‘well, it’s [SC is] £10 down there and £15 for 2 grams, whereas it’s £25 for 2 grams of the proper stuff’, so I went down and I swapped over and I was just buying it every day and smoking it every day.

1020

[Mephedrone] was also cheaper, I mean, coke was like – you see, for the street stuff like, the proper stuff that’s been cut up like 90 times, cost about £40 a gram. This stuff is costing £10 – apparently give[s] you a far longer hit and all the rest of it, so . . . That’s why I tried it, you know what I mean?

HMP1017

Like those in generation NPS, the persisters focused on the increase in cost following the ban. Both groups were affected to some degree by the ban introduced via legislation (in 2010 and 2016) and the subsequent rise in cost:

You know they’ve put it [SCs] up to £20 a gram now for flip sake, it used to be £15 for 3 grams when it first came out, then it was £20, £25, £35 a few weeks back and now it’s back up to £20 a gram.

1021

Most participants from the prison sample discussed cost of NPSs outside the prison. Those who mentioned cost inside the prison observed inflated costs for all substances, including NPSs, in comparison with street prices:

On the street for cannabis grass you pay £10 a gram, in jail you[‘re] paying £50 a gram if not more sometimes.

HMP1040

The cost of NPSs was not cited as influential for motivations to use NPSs in the prison estate. The potency of SCs and lack of detection in some drug screen analysis proved more appealing than cost. It was suggested there was little variance in the cost of traditional drugs compared with NPSs:

I was smoking [SCs] one night and I was down on the drug test the next morning and I passed, it doesn’t pick it up like for grass. It would be the same price, a gram of grass would cost you in here the same as herbal but herbal would **** you up more so people would want that in here.

HMP1012

References to non-monetary exchanges for NPSs, prescription medication and traditional illicit substances were also noted in the prisons. One participant discussed increased availability of buprenorphine (Subutex, Indivior UK Ltd) and, when asked where NPSs sat in relation to it in terms of availability, stated:

It’s like anything, if you want it you can get it, if you were struggling in here and you were in a bad way, it’s like anything, you could go out there and ask for something and there might be nothing about but if you start offering money or tobacco, you know, ‘I’ve got a bit of tobacco here, I’ll give you tobacco for it’, people then would maybe start saying, ‘well, OK, there’s always something for sale if you want it’.

HMP1004

Pleasure

Pleasure emerged as a driving force for NPS use in the narratives of some participants across the groups. Pleasure and NPSs were discussed in different ways: for some, the pleasurable experiences were recounted in isolation; however, for more participants pleasure was juxtaposed with adversity.

Pleasure was highlighted as a key driving force for the contemporary regulars. In the other groups, some participants also discussed the pleasurable effects of mephedrone, particularly in relation to first/early episodes of use. One female participant from the past experimentals group reminisced about early pleasurable experiences with mephedrone:

[Mephedrone] was supposed to be a good copy of MDMA and I suppose it kind of was, it wasn’t perfect but like you got a nice buzz and you felt the rush of coming up and stuff then . . . well, it kept you awake, probably worse than MDMA, you couldn’t sleep for a wee while after, but it made you more talkative, more chatty, a lot less self-conscious, time sort of passed and you would not have necessarily noticed time pass because you were having so much fun like dancing and chatting and having a couple of drinks.

1001

Similarly, a female participant from the persisters SG recounted her initial experience with mephedrone as pleasurable, thus leading to more regular use:

I went to a party one night and they had meph[edrone] and I took a line of it and it made me, wow, not smacked but jaw swinging and all. I felt brilliant, I felt absolutely brilliant, really really brilliant, I loved it, so that became a habit at the weekends.

1019

One male recruited from the prison sample described the pleasure associated with cognitive function/access while under the influence of mephedrone:

Meth [edrone] is sort of similar like, you know, if you got a trip on it, you know, you’re loving it like, sort of thing . . . I know I’ll only use a certain percentage of my brain like, but I know if I take certain drugs it can unlock different parts of it, you know what I mean?

HMP1007

The same participant recounted an experience with mephedrone wherein he and his friends believed they had come close to figuring out the meaning of life. When probed further about his motives for using NPSs and other substances, he stated:

People say you jump out of aeroplane[s] and get this high like, you know what I mean? Blues release dopamine same [as] with any opiate . . . that receptor in the brain . . . that dopamine, that’s what gives you the desire to do whatever, ye know? It’s just the same as jumping out of a plane. It’s just the same as hitting a jump on a motorbike. I’m addicted to what the brain can do.

HMP1007

Some participants acknowledged the pleasurable aspect of taking NPSs, such as mephedrone; however, the pleasurable effects were often juxtaposed with the negative after-effects or more long-term negative perceived impact:

It’s probably the shitiest drug I can think of actually. I mean, it’s good, it’s fun, it gives you energy, you can – everyone’s laughing and smiling and partying. It was basically free at the time, I remember.

1036

I suppose you would be flying – the E [ecstasy] sort of effect – you would be flying off your head, you would be very much enjoying it, very talkative, good craic. You were up all night, you were partying for 48 hours on the stuff with hardly any drink. Obviously it wasn’t great afterwards, but at the time it was quite good fun. Yeah, I suppose that’s about it.

1037

I tried the legal highs and I liked the legal highs more than I liked any one of the other drugs because I was hallucinating. I felt better on the legal highs but the legal highs destroyed me, they destroyed me.

HMP1022

Comments about SCs and pleasure centred around reports of positive effects but described an overriding sense of negative outcome, so, again, pleasure was juxtaposed with adversity. When one participant was asked to describe the effects of SCs after the correct dosage was reached, he stated:

The best way to describe it is like a light bulb turns on in your head and the rays go out the ways. It is like going to heaven to be honest, if there was ever a description of it, it is the best feeling in the world. I know that’s why people go back, it’s the strongest high I’ve ever had anyway.

1030

The respondent finished his description, however, by stating:

Herbal wrecks you. You couldn’t care less about anything or anyone, even yourself really.

1030

Similarly, one female respondent from the dependents group spoke about SCs and stated:

You see the buzz you get off them, it’s brilliant, I love it, but it’s wild bad for your mental health like.

1049

When discussing pleasure and vaping SCs, one male participant from the dependents group stated:

It’s hard to describe, but it was just the best feeling I’ve ever had in my life to be honest, but I know how bad that is and what it turned me into. I would have lied, cheated, stole[n] probably to get it and that’s not me. I knew that turned me into a completely different person and I’m obviously really ashamed of myself.

1026

Chapter summary

The findings described in this chapter have addressed the ways in which NPSs emerged in participants’ drug use trajectories to fulfil a range of functions. Other authors have also attempted to highlight where NPSs occupy particular niches in the overall market. Corazza and Roman-Urrestarazu150 helpfully delineate four distinct ‘niches’ that they suggest NPSs have served over time. The first concerns those who avoid breaking the law by using new substances that are legal to use (at the time of using) and that induce effects similar to those of banned substances. The second niche use is avoidance of substance use detection, for example some prisoners use SCs to avoid failing routine drug tests. 151 Third, for some the prospect of a new and interesting experience will drive them to use NPSs. Historically, this can be likened to the situation in the 1980s when ecstasy came on the market and provided an experience different to that elicited by other stimulants such as cocaine. The fourth niche use of NPSs focuses more on the motivations of drug dealers, who may benefit from selling NPSs under the pretense that they are a traditional drug.

Our findings not only strongly resonate with but also add more advanced nuance to the niches as conceptualised by Corazza and Roman-Urrestarazu. 150 In addition to use for ‘skirting the law’,150 for example, we were able to add detail about how availability was mediated by legal status. Group 2, for example, ceased using as soon as legal routes of access were closed down. The relative importance of legal status by group was again incrementally less important as we moved through groups 1 to 4. In its place, other drivers surrounding potency and cost were important. Comments from the prison population and those in services confirmed the important function served by NPSs to evade drug tests. Despite a perception of safety, as implied by legality,150 more than half of the respondents purchased NPSs on the grounds of their pleasant effects (55.7%), good availability (45.7%), enhanced sociability (35.0%) and affordability (28.6%).

Chapter summary

Recent data have indicated that a lack of knowledge on the various NPSs still exists and has not been enhanced despite the PSA or recent research. Media accounts, at times sensational, remain pivotal to information exchange. Our narrative data highlighted the mixed picture with regard to perceptions around safety and harms from use of various NPSs by respondents across our groupings. Linked to timing of onset, many of our respondents, irrespective of group, acknowledged a lack of information on the range of NPSs they were initially using. The inherent risks presented in these circumstances are significant. When mephedrone first emerged on the market in 2010, users tended to be mainly young and neophyte, non-marginalised experimenters. 153 We posit that the same appears to apply to some of our users in marginalised groups, who, although experienced polydrug users and even injectors, were taken by surprise by SCs. Recent assessments by the EMCDDA153 note the potential for further unintentional use of new synthetic opioids at a time when the distinction between the use of NPSs and illicit drugs may be diminishing. This, they note, raises public health concerns, and these concerns are shared by users who report fearing these substances.

Cultural context, in terms of exposure to and normalisation of NPSs, was associated with perceptions and experiences of risk, and was evident across all groups from the non-NPS users to those dependent on NPSs. Groups 1 and 2 reflected on safety in terms of risk of harm of using substances, including the potential physical and psychological effects of using substances and potential risk associated with the environment where substance use occurs. There was a general theme of wishing to remain in control of their behaviour, with respondents in group 2 reflecting on the significant effects of SCs and loss of control when under the influence. Decision-making was influenced by hearsay around effects (what participants have heard about people who use drugs through the media, peers and members of the community) and perceived risk. This was coupled with the scant information available on various NPSs and lack of testing. In group 3 there was evidence of the power of negative media stories as a means of information, which were for some the leverage needed to help them. Groups 3 and 4 drew on the physical, psychological and social harms associated with NPS use, and the emerging culture of harm reduction messages being passed on by peers themselves in user networks was evident. This was only possible once that wisdom had been experientially accrued over time. O’Brien et al. 18 found that, in an internet-based survey of ‘cybernauts’ (n = 183), participants considered themselves to be knowledgeable consumers, searching the web to gather knowledge about NPSs and pass on their own experiences (e.g. potential harms) to other NPS users. Retailers have capitalised on the knowledge shared by these online communities and have even reported monitoring internet forums for trends and adapting their stock accordingly. 20 The relationship between NPSs and existing traditional markets is a highly complex one, and a temporal relationship between variations in the purity of traditional substances can be observed. 23 Other authors have documented the displacement effect of the various forms of NPSs. 24

We have focused here on the harms as discussed by respondents but end with a word of caution with regard to how the media portray harms of use. Sumnall155 reported in The Guardian: ‘While the dangers of spice and other “novel psychoactive substances” are at the forefront of public consciousness, the numbers of people seeking treatment for their use are minuscule compared with those presenting with problems from using traditional cannabis’. Further, more detailed discussion on SCs now follows in Chapter 7.

Patterns of use

In total, more than half of the sample (n = 46) reported lifetime use of SCs. Very experimental use of SCs (generally confined to isolated incidents) was observed among past recreationals and contemporary regulars as well as availers. More persistent and problematic use of SCs was noted among participants in our dependents group, notably in generation NPS and persisters.

Interview data indicate patterns of SC use that largely fall on either end of the drug use continuum, that is, use was either very experimental and generally an isolated incident or use was reported as dependent:

I was addicted to it four different times and I would say the last time was the hardest time to get off, that would have been just over a year ago, but every time you smoke it you do get hooked on it every time, it just gets worse and worse to quit.

HMP1020

I spent that £1600 just all on legal highs, and I was very addicted at that stage . . . smoking it, smoking it . . . Like, I was hooked from there onwards.

HMP1023

Very few participants reported use of SCs that was more sustained than experimental but not described in terms of problem use:

I didn’t really feel addicted to it [SCs] like, but if it was there I would’ve took it.

1057

For those who did report dependency on SCs, there was consensus that tolerance developed rapidly:

Herbal scared the **** life out of me whenever I started using it, but after a while my tolerance built up, started enjoying the buzz, started using it more. Then I got too high of a tolerance and started [to] dislike it but it sort of messed me mind up, so, I came off it and now, for the **** withdrawal, hairy, but I’m just very, I’m grateful for the fact that I was only using herbal for 3 months.

1046

Your tolerance, it’s pure quick too like, you don’t know, about 4 months in I didn’t have it 1 day and I just needed it and ever since then I haven’t stopped.

1044

I was only having two or three drags every time, then within the space of a few weeks I was up to smoking a one skinner and then I was smoking a two skinner, then when I wasn’t smoking I didn’t feel normal, everything kind of just got too much.

HMP1020

When the participant above was asked about the time frame after which he noticed not feeling ‘normal’, he stated:

I would say about 5 or 6 weeks.

HMP1020

Types and sources

The range of SCs reported by brand was diverse. Specific brands included but were not limited to ‘Doob’, ‘Magic Dragon’, ‘Clockwork Orange’, ‘Damnation’, ‘Hitman’ and ‘Sky High’. Participants also made reference to the range of flavours, in terms of flavourings added to mask the taste of the solvent used, including blueberry, strawberry and strawberry shortcake. Geographical setting codes highlighted regional variations in terms of the way SC products were understood and described. A number of our participants from a more rural part of Northern Ireland referred to SCs as ‘trippy’. The majority of those from the Greater Belfast area made reference to ‘herbal’ when discussing SCs; however, it was important to ascertain whether participants were referring to ‘smokeable herbal’ or ‘herbal powder/sniff’ (i.e. synthetic stimulants). Herbal cannabis was referred to as either cannabis or ‘grass’.

The primary route of administration of SCs reported was smoking in the same way as cannabis, that is, SCs added to tobacco in a rolled joint or smoked in a pipe/joint without adding tobacco. A number of participants from the prison sample also reported SCs in the form of soaked strips of paper smoked in a joint. One participant reported vaping SCs in the form of ‘C-Liquid’ using an e-cigarette. The majority of our participants sourced SCs from headshops prior to closure or from street dealers/friends of friends (social supply). In line with survey data, only a small proportion of those who used SCs reported purchasing them online.

Perceptions of synthetic cannabinoids: physical and psychological effects

Positive reported effects of SCs included a ‘heavy buzz’ and intense ‘stone’. Although some positive effects were reported, there was consensus that the experience of using SCs was not altogether a positive one. One participant noted the effects as simultaneously positive and negative and made reference to shame experienced following use:

It’s sort of like being stoned with a few extra things, if you, I don’t know, sometimes it just gives you a sore brain, it’s like somebody puts a pile of needles in there and it’s not great but most of the time when you smoke that first bong actually your brain lights up and everything is just so much better. But I don’t know, it doesn’t make you feel good if that makes any sense.

1030

From the early stages of data collection, contradictions between initial perceptions and subsequent experiences with SCs were evident. As noted from respondent characteristic coding and cross-group comparisons, both our younger participants and our more established substance users were under the impression that SCs carried with them less risk than traditional illicit drugs. SCs were initially assumed by both groups to be a legal substance that mimicked the effects of cannabis:

People always said it was like a substitute for cannabis, it’s just like grass and that’s what got a whole heap [of people] onto it, and before you know it, then it was flung everywhere, in schools, youth clubs, the whole lot. You couldn’t turn a corner without smelling it or seeing it. And . . . it was just weird. I seen what were happy and happy-go-lucky people change over a short while of time, all on this stuff . . . taking convulsions and heart palpitations and shit.

1048

I just wanted to see what it was like, but to me then, it was safe because it was called herbal, I thought it was good for you. I would rather smoke herbal than grass or ‘blow’, that’s how it starts.

1019

I thought you could treat herbal like cannabis and just keep it like normal.

1021

The reality for the majority, however, was that the effects were far from those of cannabis in terms of physical and psychological effects, both acute and long term.

One participant from generation NPS described his first encounter with SCs and the adverse physical effects experienced:

My wee cousin found it and he brought it down to me, he thought it was grass. I smoked the bong and he cleared and I just kept saying to myself, ‘I’m going to die’, and I just blanked out. I woke up and thought everything was sweet and I walked downstairs and my ma started shouting, ‘what to **** are you on?’ and all. I turned blue and there was white stuff coming out of my mouth and all, foaming at the mouth, then she was about to ring an ambulance but I came round to myself.

1044

When asked about the stage at which the participant became aware that he was not smoking cannabis, he stated:

Yeah, it felt like a whole different thing. Just hit you 5 seconds later and I knew straight away I was ****. It was scary. Now I can smoke that like I can smoke grass, doesn’t even barely do nothing anymore.

1044

Another young person from this group focused more on the adverse psychological effects following use:

There’s about four or five stages you go through whenever you take it. Some of them are good some of them are bad. First you feel all calm, you’re all OK and stuff, then the next minute you start feeling this really, really, really bad paranoia. You think everybody is just coming to get you, you know what I mean?

1051

Adverse psychological effects of SCs were also reported by more established substance users in the persisters SG:

I’ve been taking heroin for about 13 or 14 years but I had about 4 years clean there, but I went back on it the last 3 or 4 months there. It was more the herbal when I was out [of prison]. It’s really **** with my head big time. You would take your life in an instant coming off it and wouldn’t even think twice of doing it. It’s crazy. I don’t be suicidal or anything . . . I don’t know what it is – it’s not good at all.

HMP1021

In terms of chronic use, the effects of SCs are also described as very different from those of persistent cannabis use:

I believe it’s eating your insides, it’s affecting your kidneys and it’s affecting your bladder 110%. I’ve had to get tablets for my kidneys and my bladder and everything because of it. They can’t understand why, they don’t know what’s going on, they don’t know why I’m constantly needing to go to the toilet because everything seems alright. Herbal has ate my insides. I can feel it eating inside me, I can even feel my bones rattling, I can feel it.

1019

Commonly reported adverse physical and psychological effects of SC use included and were not limited to collapse, fits/seizures, blackouts, chest pain, palpitations, cardiac arrest, vomiting, loss of appetite, weight loss, disrupted sleep, stomach pain, sweating, self-harm, lack of awareness of behaviour, severe withdrawal, paranoia, anxiety, depression, psychosis, stress and memory loss.

Literature suggests that cardiac arrest following use of SCs is typically less common than acute adverse effects. 41 Although more participants reported acute adverse effects, almost one-quarter (n = 11) of those who reported lifetime use of SCs either experienced cardiac arrest themselves or knew someone who had experienced it following use of SCs:

My normal heart rate’s between 80 and 90. My heart rate was 178. They had to actually stop my heart and restart it again. I was actually dead. They had to restart my heart again, it was beating that fast, 178 or something it was. They actually had to stop my heart and restart it again . . . that was because of the herbal mixed with the methadone. So that’s what actually put me off it for good – it scared me like, big time, big time! They actually said to me, ‘you were in a body bag, you’re lucky you came around’, you know what I mean? It actually scared me something shocking like. I was in intensive care for 2 weeks. So, big time, I’ll never be near it again, never. That’s what I said to all the kids and all . . . ‘you don’t want to end up like me’, you know what I mean? They just don’t listen to you, they just don’t listen whatsoever.

1058

It’s lethal. My mate had a heart attack on it and he still couldn’t stop smoking it, because of it, and he has just got his heart fixed and he’s still smoking it.

HMP1007

Research indicates an association between chronic use of SCs and serious cognitive impairment in relation to concentration, attention and memory beyond the period of intoxication. 159,160,174,175 One of our younger SC users in the sample reflected on the lasting cognitive effects of SC use:

It’s just a mad hit you got off it. Like, there’s all sorts of crap in that stuff, chemicals and all. Like, you see my face, my skin, when I was smoking that stuff my skin used to always break out. It’s made my face bad now. It makes my memory – I don’t have good memory and all. I can’t read, I can’t really write or nothing, because of legal highs.

HMP1018

When asked about the period during which this change in cognitive function was observed, the respondent stated that it was over a period of 1 year and went on to say:

Yeah, I was in school – I don’t know how to add up. I used to be able to do it. Read, I can’t read anymore really. Like at night, when I sleep at night, I think I’m sleeping but I’m not. All mad stuff comes into my head. I need to watch like TV to keep my mind occupied, so I do. It just changed when I smoked different like brands of it.

HMP1018

There was consensus among those who reported issues of dependency with SCs that it was ‘worse’ than any other drug they had encountered. Furthermore, a small number of participants discussed the way in which the drug became known as ‘dirty’ and use, for some, carried with it shame:

When you’re smoking it . . . well, I don’t know if it’s the same for everyone else, but you’re seeing a wee bit of shame in yourself because you’re doing it, you’re smoking the dirtiest thing I’ve ever come across.

1030

Although some degree of normalisation of SC use was evident among generation NPS participants, stigmatisation of SC use and users was also observed. Perceptions of SCs changed as the number of drug-related deaths among young people increased and the media focused on SCs and ‘spice zombies’. One of our participants who transitioned from SCs to prescription medication stated:

You see like [friend’s name], then he ended up dying. I think that’s when it kind of hit a lot of people because he would have been really, really well known . . . So when all that happened I think it kind of calmed people down. I know you are going to get the general scumbags, they’re still going to take it [SCs].

1053

One participant expressed his frustration at being asked to leave the hostel he resided in at the time of interview because of his use of SCs. He suggested that SC users are more marginalised than injecting drug users in terms of harm reduction offered by services:

See, the heroin users, they get their needles and all changed. If they find needles in their room, the sharp box goes up.

1021

It is of interest that mephedrone was also perceived as a ‘dirty’ drug in terms of effect by users; however, those who used mephedrone did not reflect on use with shame.

Motivations for use

As highlighted previously, motivations for using SCs differed across the sample. For our established users and more vulnerable participants, SCs offered the desired effects (discussed in more detail in Relationship between synthetic cannabinoids and heroin). For younger members of our dependents SG generation NPS, initial motives for use centred primarily around availability, accessibility and normalisation of use among peer groups. It became clear that SCs for this peer group were as normalised as cannabis was for previous generations:

Well, we would have went in about 11 in the morning and then there was always someone that was like 19 and they would’ve done your drink run, and you would’ve paid them . . . for doing it. So, we would’ve done that there and then we would’ve went to like [to parks] . . . that was every Saturday – Friday and Saturday – we would’ve done it. And then when it got into the summer we started, everyone started smoking herbal. I don’t know, I think it was like, the first summer it was like a big thing, it’s like 5 years ago.

1053

Among the prison population, SCs were appealing in terms of lack of detection in routine drug screening tests:

I mean that Sky High stuff, I just had a whole bad time with it, it wasn’t what I thought it would be, because I did smoke some . . . legal weed called ‘herbal haze’, that was OK and it wasn’t showing up on drug tests, so I didn’t care. I was still getting stoned, I wasn’t collapsing, it wasn’t showing on a drug test, but I suppose they can put anything into them psychoactive substances . . . It doesn’t come up on a drug test, any other drug would come up on the drug test and you would get dropped to basic or sent to the block or something, like I was smoking it one night and I was down on the drug test the next morning and I passed. It doesn’t pick it up.

HMP1012

As indicated by the participant above, evading drug tests through the use of NPSs, reduced the chance of demotion from enhanced to basic allowance in terms of privileges in the prison. This excerpt demonstrates reproduction of risk through physical setting and drug policy.

The media have highlighted the use of ‘spice pigs’ in prison whereby vulnerable prisoners are recruited to sample new strains of SCs prior to distribution among the wider prison population. Our data captured a more sinister phenomenon wherein prisoners were offered SCs for free, but on the condition that they smoked a set amount, usually in excess and more for the entertainment of other prisoners rather than actually testing the effects of the drug:

The herbal cannabis in the jail, it’s something else. There was that much people were giving it away. People were actually only getting to smoke it if they would smoke a good amount on a bucket, so then other people could sit and laugh, laugh and have fun about what way these people were taking bad effects to it.

HMP1008

Quality

Distinctions were made in terms of SCs and perceived quality with regard to the presentation of the substance on purchase. SCs purchased from a street dealer in a sealed and branded bag were considered gold standard in terms of quality. This was the case both pre and post closure of headshops for those who primarily sourced SCs from dealers.

If you get it in a normal bag, someone has went out of their way to put it into this bag, whereas if you get the sealed bag you’re getting exactly what that boy bought off the internet.

1030

Then stuff like strawberry blends, strawberry shortcake, blueberry – that was all cheaper herbal that came in baggies. That stuff was a lot weaker – it was a lot, way, way, way, way more for your money. Everybody was trying to get the sealed bag stuff. The sealed bag stuff was the stronger stuff like. That was all the Sky High, the Magic Dragon and Doob, and all that.

1046

The use of brand names makes identification of SCs and assessment of harms difficult; however, there was consensus that Sky High was the most potent of all SCs. Despite the fact that participants may not have been well versed in the evolution of SCs from first-/second-generation to third-generation products, some of the more established SC users observed the changes across time and discussed the repercussions:

The herbal Sky High, it’s the only one that affects me. The orange one used to and then once Sky High was getting banned we sort of went around all different flavours to see what one is good, and there’s one pineapple [one] that would give you a giggly effect, you wouldn’t get that. If it was berry, you wouldn’t have as much mind stuff, if you know what I mean, you were too busy laughing at nothing.

1021

You see that Sky High, people are dropping with Sky High.

1049

The one that was the strongest was the Sky High.

HMP1018

Withdrawal from synthetic cannabinoids

A number of our participants discussed issues around physical and psychological symptoms of withdrawal experienced when ceasing regular SC use. Withdrawal was described in particularly unpleasant terms by all those who reported dependency issues with SCs:

It’s wild, wild addictive like. You see, whenever I was coming off that herbal, holy ****, I’m telling you, I was sweating and everything, I was at the toilet every morning being sick, couldn’t eat, couldn’t sleep, like I couldn’t sleep without it, couldn’t do stuff without it and I couldn’t move . . . I smoked legal highs and I want it more and more and more and more and more. I got addicted to it. It was getting to the stage, every morning I was being sick, you know, nothing was coming up and if I ate anything it was coming back up, if I drank anything it was coming back up – I was just . . . I don’t know . . . I was cold, I was shivering, I was sweating, just felt like I was dying when I was coming off it. It was just the hardest – it’s a nasty, nasty, nasty drug. It’s on our streets and it needs to be **** took off our streets – because I smoked it last night and I thought it was ‘green’, I thought it was grass . . . What the ****?

1049

There was consensus that symptoms of withdrawal were experienced within 1 to 2 days of ceasing use:

The next day. You see, if I woke up and I never had nothing and I drank nothing that day . . . I would be lying there in a ball, sweat beating off me.

1049

Although the period of withdrawal was described as particularly unpleasant and akin to withdrawal from opiates, symptoms reportedly subsided after several weeks. The following section, Relationship between synthetic cannabinoids and heroin, delves further into the complex relationship between the two substances. However, it was apparent that the SC effects and withdrawal played a role in terms of accelerated pathways to more problematic/severe substance use, particularly among our younger, generation NPS SG:

I managed to get off it [SCs] there about 3 months ago now. That was awful. It [was] literally like being in hell. Your skin is on fire, your head is just far gone, like even in the hospital, like I ended up over there, it was that bad, and I was clawing at the ground and trying to rip my hair out and all and they jabbed me with diazepam, like the strongest stuff they had, and I was still losing the plot, so it’s a lot stronger than anything else I’ve ever came across in my life, even the 4 years I was smoking grass, it was nothing on the 6 months of smoking herbal. It wrecked me. I’ve barely touched anything since, apart from the odd . . . joint or something, and I would have a wee smoke of it, but I’m not going out and buying drugs really, maybe the odd Class A, but I was never addicted to them anyway, it’s just for fun rather than fuelling my drug habit.

1030

Relationship between synthetic cannabinoids and heroin

Existing research on NPSs has described the transition from injecting traditional illicit drugs to injection of NPSs (e.g. from injecting heroin/crack cocaine to mephedrone/ethylphenidate) or the transition from smoking cannabis to smoking SCs. 176 Absent in the literature, however, is the way in which SCs relate to traditional illicit drugs other than cannabis, in particular heroin. Increased prevalence of SC use among vulnerable populations is documented in the literature; however, the complex dynamic of transitioning to and from SCs, motivations for transition, accelerated pathways and associated harms are explored to a lesser extent.

A significant proportion of those who reported SC use described the effects as equally or more harmful than heroin:

It’s basically heroin, the way it is. Obviously you’re not going to jag [inject] it but it’s just the worst thing on the street by far. It makes meph[edrone] look like fairy dust, in a good way, if you know what I mean? It’s wrecking people’s lives really, really badly . . . They don’t know enough about it to make an actual choice whether to smoke it or not. It just doesn’t seem that bad. Even when I first started smoking it, no one was, ‘ah, it’s really badly addictive’. I didn’t know it was addictive until I myself was addicted to it, then everybody just out of the blue started to tell me, ‘yeah, lad, that’s really bad’, and I was like, ‘now you tell me. It’s too late to go back now’. It made me not want to smoke weed anymore either, there’s no point. If you’re smoking legal highs weed isn’t going to work. It takes everything away from you.

1030

For some participants, developing lay knowledge around SCs and their opiate-like effects resulted in them being selected as drugs of choice. This was particularly evident among our vulnerable participants (homeless population and prison sample) in terms of escapism and passing time (on streets/in prison cell). For example, one prison participant stated:

Do you see, the screws, they lock us up all the time, they just say, ‘oh, no staff’, and you’re locked up all the time and, do you see, if you smoke a joint of herbal your time flies in because you be like goofing out and all and you’ll go to sleep. It’s **** mad.

HMP1012

Two of our participants who had experienced periods of homelessness stated:

When I was sitting in my sleeping bag I used to go like that [breathes in] and smoking pipes of it. It was just to feel numb, so I didn’t feel cold, I didn’t feel embarrassed, I didn’t feel anything, I felt no emotions at all, it’s just that’s what it used to do for me.

HMP1015

I can understand the homeless ones smoking it because it’s going to keep you warm at night, it’s going to make them sleep and they don’t feel the cold. It’s the same with the heroin, they take it to block it out so they’re not cold, so they can actually sleep and not be sitting up all night scared of getting attacked.

1019

For such vulnerable groups, use of SCs (in the same way as heroin) was functional and served as a means to ease the physical and psychological suffering associated with their situation and status as individuals living on the streets.

It was evident that the relationship between SCs and heroin was bidirectional as well as concurrent and both functional and instrumental. Some participants noted that they used SCs and heroin together, others stated that SCs led them on to heroin use, others used SCs to abstain from heroin and some used SCs or heroin to temporarily substitute the other. Although the interactions described in the following sections were reported by the minority of participants, the present study’s data contribute to a virtually non-existent evidence base on the relationship between SCs and heroin and so are deemed significant.

Chapter summary

It is clear from our findings that SCs are entities worthy of separate consideration when dealing with the wider categories of NPSs. On the whole, we offer further insight and corroboration for existing evidence on a range of issues. This includes analysis on SC types, effects, perceptions and reported harms. As highlighted, variations in potency across and within brands causes difficulty in terms of risk assessment and building knowledge around dosage, effect and risk of harm. We contend that our research substantially contributes to the sparse evidence base around SCs and serious adverse effects, motivations/outcomes for less established substance users, withdrawal and the relationship between SCs and traditional illicit drugs, particularly heroin. Interview data indicate patterns of SC use that largely fall on either end of the drug use continuum, that is, use was either very experimental and generally an isolated incident or use was reported as dependent. Our findings also highlighted the inherent risk posed by participants of being unaware of the effects of SCs. This was evident across both highly experienced and less experienced user groups. This was predicated on an assumption, even among experienced heroin users, that SCs were akin to cannabis. Some participants in our study indicated that their use of SCs had provided a transition back onto heroin for them. Other, less experienced users reflected on SCs’ role in providing an accelerated pathway to heroin use. Highlighted too was the sheer intensity of withdrawal from SCs against a backdrop of limited or no medical intervention to ameliorate the very significant symptoms of withdrawal.

Key contribution 1: novel psychoactive substances in polydrug use novel psychoactive substances groups

As expounded in the preceding sections of this report, our evidence supports the argument that NPSs are best conceptualised as having a place within a polydrug use trajectory. An important finding from our extensive statistical models based on longitudinal data confirmed that there was not a distinctive ‘NPS class’. The latent classes generated from the BYDS data also evidenced the difficulty of unpicking the relative importance of a range of risk and protective factors as they relate to substance use at a population level. However, in presenting our findings we have gone to considerable lengths to clearly differentiate within this overall NPS/polydrug use premise. We were fortunate to have the detail provided by narrative accounts to help us understand the subjective interplay of the range of risk and protective factors, drug repertoires, contexts, temporal relationships and so on as recounted in the lived experience of respondents. Furthermore, the importance of these factors in their narratives was evidenced by how people presented their story and how central to their account the risk and protective factors were. As presented in preceding chapters, analysis across taxonomy groups evidenced both shared patterns and, at times, rather clear distinctions in the nature, extent and balance of risk and protective factors inherent in accounts.

Key contribution 2: novel psychoactive substances as a snare for more problem use

Seminal work by Moffitt70 highlighted the potential of a range of snares that behaved like an accelerant for antisocial behaviour. Borrowing that concept, we posit that in a polydrug use pathway our data indicate that in some instances specific NPSs operated as a snare to more problematic patterns of use in a number of ways. First, branding SCs with the descriptors ‘legal’ and ‘herbal’ by marketers as an alternative to cannabis30 conferred a tacit message of safety, or at least minimal harm. When first introduced to the scene, the level of knowledge and user wisdom surrounding these substances was negligible for respondents in our sample. Perceiving similarities to cannabis and having little or no awareness of the signs of growing dependence resulted in the case of participants in generation NPS having accelerated pathways to dependent use. Ford et al. 30 noted the possibility that brain development in adolescence may render younger users more susceptible to the potential psychotic and/or pro-convulsant effects. From our data we also suggest that this may also extend to vulnerabilities to dependence.

Ralphs et al. 54 noted the highest prevalence and problematic use of NPSs, primarily SCs, among the same vulnerable groups that have traditionally been associated with problematic Class A substance use. Indeed, as was the case in our study, many dependent users of SCs referred to past problematic use of other substances, typically heroin. However, in our study, generation NPS participants clearly do not fit that overall assertion.

For those already reporting a dependency (the persisters), the effect of SCs still took them by surprise. Many continued with use owing to effects being perceived as either functional or pleasurable, even if they were unsuspected. The subsequent interchanging of SCs and heroin thereafter was noted in several accounts, as highlighted in Chapter 7. Introduction of the PSA has sought to ensure that NPSs are no longer legal to sell. However, in this vein, our PPI discussions did highlight the potential for users to continue to perceive NPSs as being of lesser harm as a consequence of no penalty being levied for those caught in possession (without intent to supply), in contrast to penalties surrounding other substances. Ensuring awareness that these substances are not akin to cannabis remains an important message to confer to users.

Second, in the case of mephedrone, when still ‘legal’, this novel psychoactive substance acted as a conduit for crossover between scenes, as indicated by the past recreationals, where NPSs were introduced to scenes where use had hitherto been limited. This offers a mechanism for exposure to alternative and potentially problematic scenes. In this vein, the ‘moreish’ properties of mephedrone were also noted by the contemporary regulars as having the potential to alter their patterns of use, this being the case even in very drug-wise experimenters. Injection of mephedrone, albeit limited in our sample, is also indicative of a potential for crossover in modes of use. In these cases, the number of daily injection episodes of mephedrone outstrip those for heroin. Such regular injection, and the properties of mephedrone described as almost corrosive, pose greater risk in terms of injection site injury. It is acknowledged that the numbers on which these assertions are based are relatively small; however, our PPI group fully supported the validity of the arguments presented.

Key contribution 3: suggested interventions/treatment modalities mapped onto our empirical findings

In constructing our taxonomy, we located various types of NPS use in a range of polydrug trajectories. A consideration of results categorised according to each of the four groupings raises a number of important issues for policy and practice. To date, the literature has focused on categorisation of treatment according to settings10,11,13 and avoided the now defunct notion of treatment aligned to specific NPS categories. Our suggestions here also build on the NEPTUNE guidance46 and draw on other extant literature to inform the framework of suggested interventions and treatment modalities, which is presented according to group classifications generated from the current research.

Key contribution 4: messages for further research

A recent publication by the EMCDDA, Health and Social Responses to Drug Problems,8 includes comprehensive up-to-date information on responses to drug problems across Europe. This includes a section specifically on ‘the implications of novel psychoactive substances for policy and practice’.

The EMCDDA report acknowledges that understanding of patterns of novel psychoactive substance use remains poor and states that most information comes from populations and settings where problems have already occurred. Accordingly, the first major practical implication of the present research is that it provides much needed further empirical data on the lived experiences of NPS users across a range of settings, not just those in problem populations. Our study elicited data from users who did not consider their use problematic and provided comparison from some individuals who opted not to use at all, as well as those high-risk populations such as those in prison or homeless people.

Future research must generate improved epidemiological data on the extent of use, patterns of use and motivations for use, and how they evolve over time. This study has potential to immediately deliver findings to help inform the agenda of such large-scale epidemiological research by providing well-articulated nuanced accounts of how NPSs functioned in a range of polydrug use trajectories.

A further implication of our study derives from our finding on the uniqueness of the knowledge and information concerning SCs. Data point to a specific set of findings regarding the use of SCs that is not evidenced elsewhere in the literature. It was clear that the relationship between SCs and heroin was bidirectional as well as concurrent and both functional and instrumental. Highlighted too was the sheer intensity of withdrawal from SCs against a backdrop of limited or no medical intervention to ameliorate the very significant symptoms of withdrawal. In consequence, future research must focus on the symbiotic link between SCs and heroin use and how the administration of SCs is influenced by heroin use and vice versa. Furthermore, we must augment the evidence base on the withdrawal effects from SCs and adulterants to inform appropriate interventions and subsequently test their efficacy in practice.

Strengths and limitations of the study

A major strength of the study was its three-phased mixed-method design. Integration of qualitative and quantitative research paradigms is complex and our method was theoretically based and conceptually sound. The complementary integration of these co-existing and inter-related dimensions of the NPS phenomena led us to a more holistic understanding. Several integration analyses were built into the design to maximise the utility of the sequential mixed-methods design. Utilisation of the high-quality BYDS longitudinal data set was a clear asset in terms of its size and its capacity to add significant value.

For the qualitative component, we successfully recruited additional respondents across the selected sample locations and this permitted us to comprehensively answer the 11 research questions. The inclusion of several service sites, including a prison sample, allowed for a varied sample, maximising opportunities for a multiplicity of user perspectives to address our research questions. The objectives of purposive sampling were achieved, and as a result good coverage was obtained and the team concluded that thematic saturation had been reached. Benefit was obtained in the conduct and analysis of the study through the inclusion of team members who engage with the topic from different perspectives. This was augmented by a series of support groups with differing functions. The SAG comprised academic experts in the NPS area as well as methodological specialists. The PLG brought policy and practice knowledge and the service user perspective was achieved through regular updates with the BEBE, a service users forum. The research team comprised experts in both quantitative and qualitative research methods. Furthermore, the team included members with expertise in a wide variety of clinical backgrounds such as psychiatry, psychology and social work, thus improving the research by allowing multiple standpoints to influence all aspects of the research process (e.g. design, analysis and interpretation). Use of multiple viewpoints in the analysis and interpretation of the qualitative data acts as a form of multiple coding, thereby improving the validity of the findings.

The study was conducted during 2016/17. Given the fast-paced nature of NPSs, it is important to note that findings captured a particular point in time. They were also reflective of the sample generated. SGs such as MSM were not strongly represented in our sample. The PSA came into force during fieldwork and, although not particularly influential in our study, it may be influential for future work. It is also acknowledged that many of the data related to SCs and mephedrone.

The level of missing data for some of the BYDS analysis was a limitation. It is also important to note that the BYDS data were collected in 2011, so in a different context to narrative data collected. In addition, a primary constraint in any study based on self-report of drug use or any behaviour is the perceived inadequacy of other measures to triangulate within the analyses. The strength of the rapport during interviews, the reflective diaries and the time taken at the end of interviews to ensure acceptability to the participant all mitigated this to some extent. So too did the theoretical linkages back to the longitudinal data.

The present report provides an overview of what the qualitative findings tell us that is of relevance to our research questions. The richness and depth of the data set, however, allows for further important and theoretically driven analyses relating to the NPS phenomenon; these data will be presented in future research papers.

Finally, it is important to note that all our findings were shared, discussed and shaped in the various advisory fora noted. This included meetings with our SAG, several meetings of our PLG and with our service user group BEBE. The SAG supported the team by assisting us to locate and validate the findings in the current and emerging evidence base related to the various types of NPSs. How the various substances related to other substances in a polydrug use context was also shaped by the group. These discussions helped distil the key contributions of the project, which are reflected in the report. The PLG was instrumental in providing advice on how our findings could be shared with a common-sense logic that had application in the various policy and practice contexts (ranging from education through to immediate-responder settings). They informed and helped develop those sections of the report. The BEBE group too was highly engaged with the research, even before it commenced, helping us shape our submission, and engaged with the research through to publication. In terms of our findings, the BEBE group discussed with us our key hypothesis on several occasions throughout the production of the report. We amended some of the ordering and tenor of the text in the light of comments made by the group (one example was to make sure that we made it clear that the various drugs in the NPS umbrella were discussed in more detail in terms of their implications). The group noted the need to acknowledge that the focus of our findings was mostly around SCs and mephedrone and that there were other substances not covered. However, the BEBE group acknowledged the predominance of these within the Northern Ireland scene. We ensured that these limitations came across more strongly in the report as a result. All groups remain committed to further KE activity.

Scientific advisory group

Dr Caroline Chatwin, Professor Karen McElrath, Dr Russell Newcombe, Professor Harry Sumnall and Professor Marie Claire Van Hout.

Professional advisory group

Pauline Murnin, Gary Maxwell, Michael Foley, Clare Connolly, Dr Aisling Diamond, Victoria Creasy, Gary McMichael and Iain Cameron.

Contributions of authors

Kathryn Higgins, principal investigator, led the overall design of the study, contributed substantially to the analysis and led the writing of the report.

Nina O’Neill contributed significantly to the study design, jointly led the data collection and made a substantive contribution to the writing of the final report.

Leeanne O’Hara contributed significantly to the study design, jointly led the data collection and made a substantive contribution to the writing of the final report.

Julie-Ann Jordan led the secondary/quantitative analysis of the BYDS and made a substantive contribution to the writing of the final report.

Mark McCann contributed to the initial study design, contributed to the analysis plan and attended SAG meetings.

Tara O’Neill contributed to the first phase of the quantitative analysis.

Mike Clarke advised on all elements of the methodology and attended SAG meetings.

Tony O’Neill advised on the practice implications of the study, attended SAG meetings and contributed to the writing of the report.

Anne Campbell significantly contributed to writing of sections in the report relevant to treatment and practice and attended SAG and PLG meetings.

All authors were involved in this piece of research and all have approved the final version of the report.

Data-sharing statement

All data requests should be submitted to the corresponding author for consideration. Access to anonymised data may be granted following review.

Disclaimers

This report presents independent research funded by the National Institute for Health Research (NIHR). The views and opinions expressed by authors in this publication are those of the authors and do not necessarily reflect those of the NHS, the NIHR, NETSCC, the PHR programme or the Department of Health and Social Care. If there are verbatim quotations included in this publication the views and opinions expressed by the interviewees are those of the interviewees and do not necessarily reflect those of the authors, those of the NHS, the NIHR, NETSCC, the PHR programme or the Department of Health and Social Care.

Coding of longitudinal predictor measures

The school attachment and school commitment scales used in the present research were formed via factor analysis in previous research. 73 Prior to computing scales, for the school attachment, school commitment, parental control, emotional difficulties and impulse control scales, expectation–maximisation (EM) was used to impute missing values where the respondent had completed at least one item on that scale in that wave. Separate EMs were computed for each scale at each time point, which allowed the other items from the same wave to be used as predictors in each model. Details of how all the BYDS model variables were coded are as follows (Table 16 contains all items).

Coding of longitudinal outcome measures

The outcome variables were coded as follows (Table 17 contains all items).