Search

Amphetamine-Type Stimulants (ATS), such as amphetamines, MDMA, and methamphetamine are a commonly used class of illicit drugs in Europe. There is a large existing literature on motives for the use of illicit drugs, often focusing on initiation. However, few studies have explored the reasons why some people choose not to use drugs (non-use), and even fewer focus on the social processes influencing non-use of ATS specifically. We explored social processes related to normalization, and how persistent non-users negotiate their non-use in social contexts where ATS is used, using qualitative interview ( n = 21) and survey questionnaire ( n = 126) data from a mixed-method study conducted in the Netherlands and England. Our findings showed that in both countries, most participants were repeatedly exposed to ATS use, often in social or nightlife settings. Participants abstained from use for a number of reasons, including: lack of interest in illicit drug use in general; desire to maintain control over their own behavior and environment; and to avoid the associated health risks. Social processes also shaped persistent non-use of ATS, via conscious socialization with, and selection of, other non-using peers over time. Our findings contribute to the literature on the normalization thesis, showing that recreational ATS use is only partly socially accommodated and normalized among persistent non-users, suggesting differentiated normalization.

Background Amphetamine-type stimulants (ATS) are globally widely used. Scientific literature generally defines four phases of substance use (initiation, continuation, increase and decrease); however, there is limited understanding of what influences these different phases of ATS use. The ATTUNE study investigated which factors shape individual phases of use, or ATS use patterns. In this article, we report on these phases into and out of ATS use, and propose a set of recommendations for prevention, harm reduction and treatment of the different phases of ATS use. Methods Qualitative, semi-structured interviews (n = 237) were conducted in five different European countries with participants who had used ATS, varying from a few times in a lifetime to daily. Results Amphetamine and MDMA were the most commonly used ATS. Yet, types of ATS used differed between the countries. We found that people who use ATS have various motives for and dynamic patterns of ATS use with alternating phases of increase, continuation, decrease and sometimes dependence. Cessation was pursued in different ways and for diverse reasons, such as mental health problems and maturing out. Availability seemed not an issue, regardless of the type of ATS, phase or country. Conclusions These findings demonstrate that tailor-made interventions are needed for the diverse types of people who use ATS and different phases or patterns of ATS use, to reduce possible harms of use. We recommended a set of interventions for the different ATS phases. These include drug checking services, peer-led information, self-management of ATS use, mental health support to help people cope with stressful life events and prevent uncontrolled use, and follow-up support after treatment.

No abstract available.

Background Amphetamine-type stimulants (ATS) are the second most commonly used illicit drugs in Europe and globally. However, there is limited understanding of what shapes patterns of ATS use over the life course. The ATTUNE project “Understanding Pathways to Stimulant Use: a mixed methods examination of the individual, social and cultural factors shaping illicit stimulant use across Europe” aims to fill this gap. Here we report initial findings from the life course chart exercise conducted as part of qualitative interviews with ATS users and nonusers. Methods Two hundred seventy-nine in-depth qualitative interviews were conducted with five ATS user groups (current and former dependent users;current and former frequent users;non-frequent users) and one group of exposed non-ATS users in five European countries (Germany, UK, Poland, Netherlands and Czech Republic). As part of the interviews, we used life course charts to capture key life events and substance use histories. Life events were categorised as either positive, neutral or negative, and associated data were analysed systematically to identify differences between user groups. We applied statistical analysis of variance (ANOVA) and analysis of covariance (ANCOVA) to test for group differences. Results Out of 3547 life events documented, 1523 life events were categorised as neutral, 1005 life events as positive and 1019 life events as negative. Current and formerly dependent ATS users showed more negative life events for the entire life course after age adjustment. Although some group differences could be attributed to the individuals’ life course prior to first ATS use, most negative life events were associated with periods of ATS usage. A detailed analysis of the specific life domains reveals that dominantly, the social environment was affected by negative life events. Conclusions For non-dependent, frequent and non-frequent ATS users, negative life events from the period of ATS use do not become obvious in our analysed data. Besides preventing a pathway into ATS dependency, the aim of an intervention should be to reduce the harm by for example drug testing which offers also the opportunity for interventions to prevent developing a substance use dependency. For the group of dependent ATS users, our study suggests holistic, tailored interventions and specialist treatment services are needed, as a single, simple intervention is unlikely to cover all the life domains affected.

IntroductionAmphetamine-type stimulants (ATS) including amphetamine, methylenedioxymethamphetamine/‘ecstasy’, methamphetamine, synthetic cathinones and ‘Ritalin’ are the second most commonly used illicit drugs globally. Yet, there is little evidence on which factors are associated with the development of different patterns of ATS use over the life course. This study aims to examine which individual, social and environmental factors shape different pathways and trajectories of ATS consumption. The study will be conducted in five European countries: Germany, the Netherlands, Poland, Czech Republic and the UK.Methods and analysisWe will use a sequential mixed-methods study design to investigate the multiple factors (familial, social and occupational situation, critical life events, general risk behaviour, mental and physical health, satisfaction with life) that shape individual ATS use pathways. A systematic literature review will be performed to provide an overview of the current academic literature on the topic. In module 1, qualitative semistructured interviews (n=ATS users and non-users) will be conducted to explore individual experiences of, and perspectives on, dynamics of change in stimulant consumption patterns. In module 2, structured questionnaires (n=2000 ATS users and non-users) will be administered via tablet computers to validate and enhance the generalisability of the interview findings. Data integration will take place at two key points. First, during the study, where the findings from the first qualitative interviews will inform the design of the structured questionnaire. Second, at the end of the study, where mixed methods data will be brought together to generate an in-depth, contextualised understanding of the research topic.Ethics and disseminationThe study has been approved by the respective responsible ethics committee in each participating country. Data will be treated confidentially to ensure participants’ anonymity. Findings will be disseminated in peer-reviewed scientific journals, national and international conferences, and in briefings for policy and practice.

Many cannabis users ‘mature out’ of their drug use, and factors of cannabis use cessation have been identified. However, very little in-depth knowledge is available about the mechanisms underlying this phenomenon. Criminological studies have gained interesting insights in desistance from crime, yet these perspectives are rarely used in drug research. This qualitative, three-year longitudinal study explored the processes involved in desistance from frequent cannabis use for young adults. Using a narrative approach, desisters (frequent users who successfully quit their cannabis use) and persisters (frequent users with a persistent desire and unsuccessful attempts to quit) were compared. In the course of the study, desisters mainly exhibited increasing agency and goal setting, established strategies to achieve these goals, and could envision another self. Desistance was generally induced by life events that became turning points. Persisters experienced largely similar events, but lacked goals and strategies and held external factors responsible for their life course and failed quit attempts. Identity change is at the core of desistance from frequent cannabis use, and the meaning-giving to life events and experiences is essential. Agency is a necessary ingredient for desistance, develops over time and through action, and leads to a new drug-free identity with desistance in turn increasing agency.

Aims: To examine the course and the predictors of the persistence of cannabis dependence. Methods: Through cannabis outlets and chain referral, a prospective enriched community cohort of 207 young adults (aged 18-30) with DSM-IV cannabis dependence at baseline (T0) was formed and followed-up after 1.5 (T1) and 3 (T2) years. The presence of cannabis dependence, cannabis-related problems, functional impairment and treatment was assessed using the Composite International Diagnostic Interview (CIDI 3.0) and the Sheehan Disability Scale (SDS). Predictors of persistence were lifetime cannabis abuse and dependence symptoms, cannabis use characteristics, distant vulnerability factors (e.g. childhood adversity, family history of psychological/substance use problems, impulsivity, mental disorders), and proximal stress factors (recent life events, social support). Results: Four groups were distinguished: persistent dependent (DDD: 28.0%), stable non-persistent (DNN: 40.6%), late non-persistent (DDN: 17.9%) and recurrent dependent (DND: 13.5%). At T2, persisters (DDD) reported significantly more (heavy) cannabis use and cannabis problems than non-persisters (DNN/DDN/DND). Treatment seeking for cannabis-related problems was rare, even among persisters (15.5%). The number (OR = 1.23 (1.03-1.48)) and type (‘role impairment' OR = 2.85 (1.11-7.31), ‘use despite problems' OR = 2.34 (1.15-4.76)) of lifetime cannabis abuse/dependence symptoms were the only independent predictors of persistence with a total explained variance of 8.8%. Conclusions: Persistence of cannabis dependence in the community is low, difficult to predict, and associated with a negative outcome. The substantial proportion of stable non-persisters suggests that screening and monitoring or low-threshold brief interventions may suffice for many non-treatment-seeking cannabis-dependent people. However, those with many lifetime abuse/dependence symptoms may benefit from more intensive interventions.

BackgroundThe link between leisure and cannabis use has been widely studied, but less so for young adults, and rarely with a focus on frequent cannabis use. Also, little is known about how changes in leisure develop over time and how they are related to transitions in cannabis use and dependence.MethodAs part of a 3-year longitudinal project, in a qualitative study 47 frequent male and female young adult cannabis users with (n = 23) and without (n = 24) dependence at baseline were interviewed in-depth after 1.5 and 3 years.ResultsFrequent cannabis users (at baseline ≥3 days per week in the past 12 months) are involved in similar leisure activities as the general young adult population and live rather conventional lives, generally away from a delinquent subculture. They mostly regulate their cannabis use to leisure time, to enhance other leisure activities, including socialising and video gaming. While they often give precedence to responsibilities (e.g. work and study), dependent and non-dependent users differed in whether they actively adapted their leisure activities to their cannabis use, or their cannabis use to their leisure time. Both types of and time spent on leisure activities were associated with transitions in use and dependence.ConclusionsWhile our findings generally support the normalisation thesis, it is questionable whether frequent but non-problematic cannabis use is socially accepted in wider society. This study also questions the diagnostic dependence vs. non-dependence dichotomy, and adds finer distinctions to the concept of cannabis dependence. Implications for prevention and treatment include facilitating structured spending of leisure time (e.g. sports), and targeting frequent users who spent much leisure time video gaming at home.

BackgroundandAims Increased delta-9-tetrahydrocannabinol (THC) concentrations in cannabis may lead to higher THC exposure, cannabis dependence and treatment need, but users may also adapt the actual intake of THC through reduced inhalation of THC containing smoke (titration). We investigated whether consumers of stronger cannabis use less cannabis per joint or inhale less smoke than those using less potent cannabis and whether these factors predict cannabis dependence severity.Methods Heavy cannabis users (n = 98) brought their own cannabis, rolled a joint and smoked it ad libitum in a naturalistic setting. We analysed the content of the joint, its association with smoking behaviour and the cross-sectional and prospective (1.5-year follow-up) relations between smoking behaviour and cannabis dependence severity (total number of DSM-IV dependence symptoms). Results THC concentration in cannabis (range 1.10-24.70%) was correlated positively with cannabis dose per joint (b = 0.008, P = 0.01), but the resulting THC concentration per joint (range 0.24-15.72%) was associated negatively with inhalation volume (b =− 0.05, P = 0.03). Smoking behaviour measures (number of puffs, inhaled volume, reduction of puff volume and puff duration while smoking) predicted follow-up dependence severity, independently of baseline dependence severity and monthly THC dose (number of joints × cannabis dose × cannabis THC concentration). Monthly THC dose only predicted follow-up dependence severity when unadjusted for baseline severity. Conclusions Cannabis users titrate their delta-9-tetrahydrocannabinol intake by inhaling lower volumes of smoke when smoking strong joints, but this does not fully compensate for the higher cannabis doses per joint when using strong cannabis. Thus, users of more potent cannabis are generally exposed to more delta-9-tetrahydrocannabinol. Smoking behaviour appears to be a stronger predictor for cannabis dependence severity than monthly delta-9-tetrahydrocannabinol dose.

The Severity of Dependence Scale (SDS) measures with five items the degree of psychological dependence on several illicit drugs, including cannabis. Its psychometric properties have not yet been examined in young adult frequent cannabis users, an eminently high-risk group for cannabis dependence. Internal consistency and criterion validity of the SDS were investigated within an enriched community based sample of 577 Dutch frequent (≥ three days per week in the past 12 months) cannabis users between 18-30 years. Criterion validity was tested against the Composite International Diagnostic Interview (CIDI) 3.0 DSM-IV diagnosis cannabis dependence, and psychometric properties were assessed separately for males and females and for ethnic subgroups. Principal component analysis showed that all items of the scale loaded on a single factor and reliability of the SDS total score was good (Cronbach's α = 0.70). However, criterion validity against the CIDI diagnosis cannabis dependence was low: area under curve (AUC) was 0.68 (95% confidence interval: 0.64-0.73) and at the optimal differentiating cut-off (SDS ≥ 4), sensitivity was 61.3% and specificity 63.5%. Results were similar for subgroups on gender and ethnicity. While internal consistency of the SDS is good, its use as a screener to differentiate between dependence and non-dependence within populations of young adult frequent cannabis users is not recommended.

Aims To compare the prevalence of mental disorders between frequent cannabis users with and without dependence and the general population. Design Cross-sectional comparison of interview data. Setting Enriched community sample of frequent cannabis users and a representative sample of non-users and non-frequent users from the general population. Participants A total of 521 young adult (aged 18–30 years) frequent cannabis users, 252 of whom were with DSM-IV cannabis dependence (D+) and 269 without DSM-IV cannabis dependence (D−), and 1072 young adults from the general population. Measurements Multinomial logistic regression was used to compare groups regarding the presence of DSM-IV mental disorders. Detailed measures of cannabis use, childhood adversity and other substance use were considered confounders. Findings Compared with the general population, externalizing disorders were more prevalent in D− [odds ratio (OR) = 8.91, P

BackgroundFrequent cannabis users are at high risk of dependence, still most (near) daily users are not dependent. It is unknown why some frequent users develop dependence, whereas others do not. This study aims to identify predictors of first-incidence DSM-IV cannabis dependence in frequent cannabis users.MethodsA prospective cohort of frequent cannabis users (aged 18-30, n = 600) with baseline and two follow-up assessments (18 and 36 months) was used. Only participants without lifetime diagnosis of DSM-IV cannabis dependence at baseline (n = 269) were selected. Incidence of DSM-IV cannabis dependence was established using the Composite International Diagnostic Interview version 3.0. Variables assessed as potential predictors of the development of cannabis dependence included sociodemographic factors, cannabis use variables (e.g., motives, consumption habits, cannabis exposure), vulnerability factors (e.g., childhood adversity, family history of mental disorders or substance use problems, personality, mental disorders), and stress factors (e.g., life events, social support).ResultsThree-year cumulative incidence of cannabis dependence was 37.2% (95% CI = 30.7-43.8%). Independent predictors of the first incidence of cannabis dependence included: living alone, coping motives for cannabis use, number and type of recent negative life events (major financial problems), and number and type of cannabis use disorder symptoms (impaired control over use). Cannabis exposure variables and stable vulnerability factors did not independently predict first incidence of cannabis dependence.ConclusionsIn a high risk population of young adult frequent cannabis users, current problems are more important predictors of first incidence cannabis dependence than the level and type of cannabis exposure and stable vulnerability factors.

In a Dutch longitudinal study on the dynamics of cannabis dependence, at baseline 600 frequent cannabis users (? 3 days cannabis use per week in past 12 months) aged 18–30 years were interviewed. Nearly half of all participants (42%) met DSM-IV criteria for cannabis dependence in the 12 months prior to the interview. Participants were recruited by respondent-driven sampling; referrals were understood as proxy for social networks to explore peer associations and social exclusion. Analyses revealed that networks of frequent cannabis users were mostly heterogeneous. Cannabis dependence did not emerge as a main selector. However, within segments of networks some clustering of cannabis dependence (indicating differential inclusion), sex and ethnicity was found. Methodological questions are discussed regarding the applicability of respondent-driven sampling in noninjecting, nonmarginalized drug users. The study's limitations are noted.

This paper presents an overview of the prospective cohort design of the Dutch Cannabis Dependence (CanDep) study, which investigates (i) the three-year natural course of frequent cannabis use (≥ three days per week in the past 12 months) and cannabis dependence; and (ii) the factors involved in the transition from frequent non-dependent cannabis use to cannabis dependence, and remission from dependence. Besides its scientific relevance, this knowledge may contribute to improve selective and indicated prevention, early detection, treatment and cannabis policies. The secondary objectives are the identification of factors related to treatment seeking and the validation of self report measures of cannabis use. Between September 2008 and April 2009, baseline data were collected from 600 frequent cannabis users with an average age of 22.1 years, predominantly male (79.3%) and an average cannabis use history of 7.1 years; 42.0% fulfilled a (12-month DSM-IV) diagnosis of cannabis dependence. The response rate was 83.7% after the first follow up at 18 months. The second and last follow-up is planned at 36 months. Computer assisted personal interviews (CAPI) were conducted which covered: cannabis use (including detailed assessments of exposure, motives for use and potency preference); use of other substances; DSM-IV internalizing and externalizing mental disorders; treatment seeking; personality; life events; social support and social functioning. Copyright © 2011 John Wiley & Sons, Ltd.

The Marijuana Motives Measure (MMM) has so far been examined mainly in student populations, often with relatively limited involvement in cannabis use. This study evaluated the factor structure of the MMM in a demographically mixed sample of 600 young adult (18–30 years) frequent (≥ 3 days per week) cannabis users in the Netherlands. Analysis confirmed a five-factor solution, denoting coping, enhancement, social, conformity and expansion motives. Additionally, the original MMM was extended with two items (boredom and habit), which formed a distinct, internally consistent sixth factor labelled routine motives. In a multivariable logistic regression analysis, coping and routine motives showed significant associations with 12-month DSM-IV cannabis dependence. The results suggest general reliability and validity of the MMM in a heterogeneous population of experienced cannabis users.

The majority of cannabis dependent people do not seek professional treatment. Whether this indicates a ‘treatment gap’ depends on clinical characteristics of dependence in absence of treatment. In addition, motives for (not) seeking treatment are largely unknown. The current study compares 70 cannabis dependent patients with 241 non-treatment seeking cannabis dependent community subjects. Treatment facilitators were assessed in the 70 patients and barriers in 160 of the 241 dependent non-treatment seekers, who precluded to seek treatment. Compared to non-treatment seekers, patients reported more symptoms of dependence, more cannabis use, more mental health problems and more functional impairments due to physical and/or psychological problems. Patients also more often perceived lack of social support, while they received more support from family or friends, who also more often pressured to seek treatment. Patients reported mental health problems and functional impairment as facilitators to seek treatment. Cannabis dependent ‘precluders’ reported desire for self-reliance, preference for informal help from family or friends, and absent treatment need as their main reasons not to seek treatment. Non-treatment seekers showed better clinical characteristics compared with patients, and often deemed treatment unnecessary, suggestive of a limited ‘treatment gap’. While indeed treatment may often be unnecessary when it is not sought, some may still benefit from low threshold interventions, which should consider the desire for self-reliance and the preference for informal help, and would allow referral of severe cases to more intensive interventions. ___De meeste mensen met cannabisafhankelijkheid zoeken geen hulp. Een ‘behandelkloof’ ontstaat als niet-hulpzoekers niet spontaan herstellen en ernstige klinische kenmerken hebben. Het is onbekend in hoeverre hier sprake van is. Ook is er nauwelijks iets bekend over de redenen om al dan niet hulp te zoeken. In dit onderzoek werden 70 cannabisafhankelijke patiënten in de verslavingszorg vergeleken met 241 cannabisafhankelijke gebruikers uit de algemene bevolking die geen hulp hadden gezocht. Redenen om al dan niet hulp te zoeken werden vastgesteld bij alle 70 patiënten en bij 160 van de 241 cannabisafhankelijke gebruikers die zeiden in geval van cannabisproblemen geen hulp te zullen zoeken. Vergeleken met niet-hulpzoekers rapporteerden patiënten meer afhankelijkheidscriteria, meer cannabisgebruik, meer psychische problemen en meer beperkingen in het functioneren als gevolg van lichamelijke en/of psychische problemen. Patiënten ervoeren vaker dan niet-hulpzoekers een tekort aan sociale steun, ondanks dat zij vaker steun van vrienden of familie kregen, die ook vaker aandrongen om hulp te zoeken. Geestelijke gezondheidsproblemen en hinder in het functioneren waren de meestgenoemde redenen om hulp te zoeken. De belangrijkste motieven om geen hulp te zoeken waren: zelf willen stoppen, liever stoppen met hulp van familie of vrienden en behandeling voor cannabisproblematiek niet nodig vinden. Al met al lijkt de ‘behandelkloof’ mee te vallen, want vergeleken met patiënten in de verslavingszorg hebben niet-hulpzoekers met cannabisafhankelijkheid minder ernstige klinische kenmerken en vinden ze hulp vaak onnodig. Behandeling lijkt vaak onnodig voor niet-hulpzoekers, hoewel sommigen baat zouden kunnen hebben bij laagdrempelige interventies die rekening houden met de behoefte zelf te stoppen en met ondersteuning door familie of vrienden. Dergelijke interventies zouden daarnaast doorverwijzing van degenen met ernstige problemen kunnen faciliteren.

BackgroundRelatively few cannabis dependent people seek treatment and little is known about determinants of treatment seeking.MethodsTreatment determinants were compared among 70 DSM-IV cannabis dependent patients and 241 non-treatment seeking DSM-IV cannabis dependent community subjects. In addition, perceived facilitators for treatment seeking were assessed in patients, whereas perceived barriers were assessed in 160/241 cannabis dependent community subjects not prepared to seek treatment (precluders), of whom 63/160 showed an objective treatment need, and 30/241 showed a subjective treatment need.ResultsCompared to non-treatment seekers, patients reported more cannabis use (176.9 versus 82.8 joints monthly), more symptoms of dependence (5.6 versus 4.5), higher perceived lack of social support (70.0% versus 41.1%), more pressure to seek treatment (58.6% versus 21.6%), a more positive attitude to treatment, and more previous treatments. In addition, patients reported more mental health problems (internalising disorders 57.1% versus 24.5%; externalising disorders 52.9% versus 35.3%) and more functional impairments (8.4 versus 4.8 monthly days out of role). Cannabis dependent ‘precluders’ reported desire for self-reliance (50.0%), preference for informal help (22.5%), and absent treatment need (16.9%) as their main reasons not to seek treatment, whereas cannabis dependent community subjects with a subjective treatment need mainly expressed desire for self-reliance (36.7%), treatment ineffectiveness (16.7%), and avoiding stigma (13.3%).ConclusionsFunctional impairment, mental health problems and social pressure are important reasons to seek treatment in people with cannabis dependence. Treatment participation might improve if desire for self-reliance and the preference for informal help are considered, and perceived ineffectiveness of treatment and stigmatisation are publicly addressed.

Increased delta-9-tetrahydrocannabinol (THC) concentrations in cannabis may lead to higher THC exposure, cannabis dependence and treatment need, but users may also adapt the actual intake of THC through reduced inhalation of THC containing smoke (titration). We investigated whether consumers of stronger cannabis use less cannabis per joint or inhale less smoke than those using less potent cannabis and whether these factors predict cannabis dependence severity.Heavy cannabis users (n = 98) brought their own cannabis, rolled a joint and smoked it ad libitum in a naturalistic setting. We analysed the content of the joint, its association with smoking behaviour and the cross-sectional and prospective (1.5-year follow-up) relations between smoking behaviour and cannabis dependence severity (total number of DSM-IV dependence symptoms).THC concentration in cannabis (range 1.10-24.70%) was correlated positively with cannabis dose per joint (b = 0.008, P = 0.01), but the resulting THC concentration per joint (range 0.24-15.72%) was associated negatively with inhalation volume (b = -0.05, P = 0.03). Smoking behaviour measures (number of puffs, inhaled volume, reduction of puff volume and puff duration while smoking) predicted follow-up dependence severity, independently of baseline dependence severity and monthly THC dose (number of joints × cannabis dose × cannabis THC concentration). Monthly THC dose only predicted follow-up dependence severity when unadjusted for baseline severity.Cannabis users titrate their delta-9-tetrahydrocannabinol intake by inhaling lower volumes of smoke when smoking strong joints, but this does not fully compensate for the higher cannabis doses per joint when using strong cannabis. Thus, users of more potent cannabis are generally exposed to more delta-9-tetrahydrocannabinol. Smoking behaviour appears to be a stronger predictor for cannabis dependence severity than monthly delta-9-tetrahydrocannabinol dose.

The Severity of Dependence Scale (SDS) measures with five items the degree of psychological dependence on several illicit drugs, including cannabis. Its psychometric properties have not yet been examined in young adult frequent cannabis users, an eminently high‐risk group for cannabis dependence. Internal consistency and criterion validity of the SDS were investigated within an enriched community based sample of 577 Dutch frequent (≥ three days per week in the past 12 months) cannabis users between 18–30 years. Criterion validity was tested against the Composite International Diagnostic Interview (CIDI) 3.0 DSM‐IV diagnosis cannabis dependence, and psychometric properties were assessed separately for males and females and for ethnic subgroups. Principal component analysis showed that all items of the scale loaded on a single factor and reliability of the SDS total score was good (Cronbach's α = 0.70). However, criterion validity against the CIDI diagnosis cannabis dependence was low: area under curve (AUC) was 0.68 (95% confidence interval: 0.64–0.73) and at the optimal differentiating cut‐off (SDS ≥ 4), sensitivity was 61.3% and specificity 63.5%. Results were similar for subgroups on gender and ethnicity. While internal consistency of the SDS is good, its use as a screener to differentiate between dependence and non‐dependence within populations of young adult frequent cannabis users is not recommended. Copyright © 2013 John Wiley & Sons, Ltd.

Life course theory considers events in study and work as potential turning points in deviance, including illicit drug use. This qualitative study explores the role of occupational life in cannabis use and dependence in young adults. Two and three years after the initial structured interview, 47 at baseline frequent cannabis users were interviewed in-depth about the dynamics underlying changes in their cannabis use and dependence. Overall, cannabis use and dependence declined, including interviewees who quit using cannabis completely, in particular with students, both during their study and after they got employed. Life course theory appeared to be a useful framework to explore how and why occupational life is related to cannabis use and dependence over time. Our study showed that life events in this realm are rather common in young adults and can have a strong impact on cannabis use. While sometimes changes in use are temporary, turning points can evolve from changes in educational and employment situations; an effect that seems to be related to the consequences of these changes in terms of amount of leisure time and agency (i.e., feelings of being in control).

In a 3-year qualitative longitudinal study the role of social relationships in cannabis use and dependence in young adults (all frequent users at baseline) was explored. Overall, cannabis use and dependence declined. Changes in use were, for a considerable part, attributable to processes and life events in social relationships with peers and partners, while parents had little influence. Negatively experienced events often triggered increased use and positively experienced events decreased use. Participants often adapted their use to others, depending on associate's use. Underlying mechanisms appear related to both socialization and selection. Gender-specific processes occurred, particularly with regard to partners; females selected using partners and males nonusing partners, and subsequently cannabis use increased (females) or decreased (males) by socialization. Transitions in cannabis dependence could be explained by using peers, cohabitation and, for females, a new partnership. Persistent and newly nondependent participants were less susceptible to social influences than dependent interviewees.

To compare the prevalence of mental disorders between frequent cannabis users with and without dependence and the general population.Cross-sectional comparison of interview data.Enriched community sample of frequent cannabis users and a representative sample of non-users and non-frequent users from the general population.A total of 521 young adult (aged 18-30 years) frequent cannabis users, 252 of whom were with DSM-IV cannabis dependence (D+) and 269 without DSM-IV cannabis dependence (D-), and 1072 young adults from the general population.Multinomial logistic regression was used to compare groups regarding the presence of DSM-IV mental disorders. Detailed measures of cannabis use, childhood adversity and other substance use were considered confounders.Compared with the general population, externalizing disorders were more prevalent in D- [odds ratio (OR) = 8.91, P 0.001] and most prevalent in D+ (OR = 17.75, P 0.001), but internalizing disorders were associated only with D+ (mood OR = 4.15, P 0.001; anxiety OR = 2.20, P = 0.002). Associations were attenuated (and often became non-significant) after correction for childhood adversity and substance use other than cannabis. However, the prevalence of mental disorders remained higher in D+ compared with D- (OR = 2.40, P 0.001), although cannabis use patterns were remarkably similar.Cannabis use patterns, childhood adversity and the use of other substances are similar in dependent and non-dependent frequent cannabis users. With the exception of more externalizing disorders, the mental health condition of non-dependent frequent cannabis users is similar to that of the general population, whereas it is worse in dependent frequent cannabis users.