title: Mental health differences between frequent cannabis users with and without dependence and the general population.
abstract: OBJECTIVE
  To compare the prevalence of mental disorders between frequent cannabis users with and without dependence and the general population.
  
  
  METHODS
  Cross-sectional comparison of interview data.
  
  
  METHODS
  Enriched community sample of frequent cannabis users and a representative sample of non-users and non-frequent users from the general population.
  
  
  METHODS
  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.
  
  
  METHODS
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Netherlands Institute of Mental Health and Addiction, Utrecht, the Netherlands. 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: Margreet
authors.initials: M
authors.lastname: Ten Have
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; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D002189:Marijuana Abuse / Q000453:epidemiology / Q000523:psychology*; D008385:Marijuana Smoking / Q000453:epidemiology / Q000523:psychology*; D001523:Mental Disorders / Q000453:epidemiology*; D009042:Motivation; D009426:Netherlands / Q000453:epidemiology; D015995:Prevalence; D012959:Socioeconomic Factors; D055815:Young Adult
keywords: Dependence; frequent cannabis use; general population; mental disorders