title: Predicting the transition from frequent cannabis use to cannabis dependence: a three-year prospective study.
abstract: 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.
  
  
  METHODS
  A 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).
  
  
  RESULTS
  Three-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.
  
  
  CONCLUSIONS
  In 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.
authors.affiliation: Trimbos Institute, Netherlands Institute of Mental Health and Addiction, PO Box 725, 3500 AS Utrecht, The Netherlands. Electronic address: ppol@trimbos.nl.
authors.forename: Peggy
authors.initials: P
authors.lastname: van der Pol
authors.forename: Nienke
authors.initials: N
authors.lastname: Liebregts
authors.forename: Ron
authors.initials: R
authors.lastname: de Graaf
authors.forename: Dirk J
authors.initials: DJ
authors.lastname: Korf
authors.forename: Wim
authors.initials: W
authors.lastname: van den Brink
authors.forename: Margriet
authors.initials: M
authors.lastname: van Laar
mesh_terms: D000293:Adolescent; D000328:Adult; D039721:Diagnostic and Statistical Manual of Mental Disorders; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D002189:Marijuana Abuse / Q000453:epidemiology* / Q000523:psychology; D008385:Marijuana Smoking / Q000453:epidemiology* / Q000523:psychology; D009426:Netherlands / Q000453:epidemiology; D010551:Personality; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012044:Regression Analysis; D015203:Reproducibility of Results; D012307:Risk Factors; D012959:Socioeconomic Factors; D013315:Stress, Psychological / Q000150:complications / Q000523:psychology; D055815:Young Adult
keywords: Cannabis dependence; Exposure; Frequent cannabis use; Longitudinal; Risk factors