title: Cannabis use as an indicator of risk for mental health problems in adolescents: a population-based study at secondary schools.
abstract: BACKGROUND
  Although the association between cannabis use and a wide range of psychiatric symptoms is fairly well established, it is not clear whether cannabis use is also a risk factor for general mental health problems at secondary school. Method A total of 10 324 secondary school children aged 11-16 years, participating in an ongoing Public Health Service School Survey, gave information on demographics, substance use, school factors and stressful life events and completed the Strengths and Difficulties Questionnaire (SDQ).
  
  
  RESULTS
  Cannabis use in the past month was associated with a clinically relevant score on the SDQ [unadjusted odds ratio (OR) 4.46, 95% confidence interval (CI) 3.46-5.76]. Other risk factors associated with poor psychosocial functioning were: a low level of education, alcohol use, cigarette smoking, hard drug use, frequent truancy, an unfavourable school evaluation, feeling unsafe at school, being victimized, frequent absence due to illness, a mentally ill parent, molestation by a parent, financial problems and feeling distressed by an adverse event. In a full model adjusting for these risk factors, cannabis was not significantly associated with mental health problems, although an association at trend level was apparent. Of these risk factors, regular alcohol use, cigarette smoking, hard drug use, frequent truancy, an unfavourable school evaluation and frequent absence due to illness were also associated with cannabis use.
  
  
  CONCLUSIONS
  The association between cannabis use and poor psychosocial functioning in adolescence is due, at least in part, to confounding by other risk factors. Thus, cannabis use can best be viewed as an indicator of risk for mental health problems in adolescence.
authors.affiliation: Rudolf Magnus Institute of Neuroscience, University Medical Centre Utrecht, Department of Psychiatry, Utrecht, The Netherlands. W.vanGastel@umcutrecht.nl
authors.forename: W A
authors.initials: WA
authors.lastname: van Gastel
authors.forename: W
authors.initials: W
authors.lastname: Tempelaar
authors.forename: C
authors.initials: C
authors.lastname: Bun
authors.forename: C D
authors.initials: CD
authors.lastname: Schubart
authors.forename: R S
authors.initials: RS
authors.lastname: Kahn
authors.forename: C
authors.initials: C
authors.lastname: Plevier
authors.forename: M P M
authors.initials: MP
authors.lastname: Boks
mesh_terms: D000293:Adolescent; D000428:Alcohol Drinking / Q000453:epidemiology; D058445:Bullying / Q000523:psychology; D002648:Child; D002649:Child Abuse / Q000523:psychology / Q000706:statistics & numerical data; D016241:Child of Impaired Parents / Q000523:psychology / Q000706:statistics & numerical data; D004522:Educational Status; D005260:Female; D006801:Humans; D008297:Male; D008385:Marijuana Smoking / Q000453:epidemiology* / Q000523:psychology; D001523:Mental Disorders / Q000453:epidemiology* / Q000523:psychology; D009426:Netherlands; D016017:Odds Ratio; D012307:Risk Factors; D012907:Smoking / Q000453:epidemiology