Individual, Social, and Environmental Factors Associated with Different Patterns of Stimulant Use: A Cross-Sectional Study from Five European Countries.

Introduction: Amphetamine-type stimulants (ATSs) are the second most commonly consumed class of illicit drugs globally, but there is limited understanding of the precise factors associated with problematic versus controlled ATS consumption. This exploratory study aimed to identify which individual, social, and environmental factors are associated with different patterns of ATS use over time.

Methods: Cross-sectional surveys were conducted in Germany, England, The Netherlands, Poland, and the Czech Republic via face-to-face computer-assisted personal interviews to collect data on different user groups.

Different phases of ATS use call for different interventions: a large qualitative study in Europe.

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.

Using life course charts to assess and compare trajectories of amphetamine type stimulant consumption in different user groups: a cross-sectional study.

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.

Understanding pathways to stimulant use: a mixed-methods examination of the individual, social and cultural factors shaping illicit stimulant use across Europe (ATTUNE): study protocol.

Introduction: Amphetamine-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.

Three-Year Course of Cannabis Dependence and Prediction of Persistence.

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.

Reliability and validity of the Marijuana Motives Measure among young adult frequent cannabis users and associations with cannabis dependence.

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.

The role of leisure and delinquency in frequent cannabis use and dependence trajectories among young adults.

Background: The 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.

Method: As 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.

Cross-sectional and prospective relation of cannabis potency, dosing and smoking behaviour with cannabis dependence: an ecological study.

Background And Aims: 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.

Facilitators and barriers in treatment seeking for cannabis dependence.

Background: Relatively few cannabis dependent people seek treatment and little is known about determinants of treatment seeking.

Methods: Treatment 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.

The Role of Study and Work in Cannabis Use and Dependence Trajectories among Young Adult Frequent Cannabis Users.

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.

Predicting the transition from frequent cannabis use to cannabis dependence: a three-year prospective study.

Background: Frequent 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.

Reliability and validity of the Severity of Dependence Scale for detecting cannabis dependence in frequent cannabis users.

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.

Validation of self-reported cannabis dose and potency: an ecological study.

Aims: To assess the reliability and validity of self-reported cannabis dose and potency measures.

Design: Cross-sectional study comparing self-reports with objective measures of amount of cannabis and delta-9-tetrahydrocannabinol (THC) concentration.

Setting: Ecological study with assessments at participants' homes or in a coffee shop.

Mental health differences between frequent cannabis users with and without dependence and the general population.

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.

The Dutch Cannabis Dependence (CanDep) study on the course of frequent cannabis use and dependence: objectives, methods and sample characteristics.

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.