title: A randomized controlled trial testing the efficacy of a brief cannabis universal prevention program among adolescents in primary care.
abstract: OBJECTIVE
  To examine the efficacy of a brief intervention delivered by a therapist (TBI) or a computer (CBI) in preventing cannabis use among adolescents in urban primary care clinics.
  
  
  METHODS
  A randomized controlled trial comparing: CBI and TBI versus control.
  
  
  METHODS
  Urban primary care clinics in the United States.
  
  
  METHODS
  Research staff recruited 714 adolescents (aged 12-18 years) who reported no life-time cannabis use on a screening survey for this study, which included a baseline survey, randomization (stratified by gender and grade) to conditions (control; CBI; TBI) and 3-, 6- and 12-month assessments.
  
  
  METHODS
  Using an intent-to-treat approach, primary outcomes were cannabis use (any, frequency); secondary outcomes included frequency of other drug use, severity of alcohol use and frequency of delinquency (among 85% completing follow-ups).
  
  
  RESULTS
  Compared with controls, CBI participants had significantly lower rates of any cannabis use over 12 months (24.16%, 16.82%, respectively, P < 0.05), frequency of cannabis use at 3 and 6 months (P < 0.05) and other drug use at 3 months (P < 0.01). Compared with controls, TBI participants did not differ in cannabis use or frequency, but had significantly less other drug use at 3 months (P < 0.05), alcohol use at 6 months (P < 0.01) and delinquency at 3 months (P < 0.01).
  
  
  CONCLUSIONS
  Among adolescents in urban primary care in the United States, a computer brief intervention appeared to prevent and reduce cannabis use. Both computer and therapist delivered brief interventions appeared to have small effects in reducing other risk behaviors, but these dissipated over time.
authors.affiliation: Department of Psychiatry, University of Michigan, Ann Arbor, MI, USA.
authors.forename: Maureen A
authors.initials: MA
authors.lastname: Walton
authors.forename: Stella
authors.initials: S
authors.lastname: Resko
authors.forename: Kristen L
authors.initials: KL
authors.lastname: Barry
authors.forename: Stephen T
authors.initials: ST
authors.lastname: Chermack
authors.forename: Robert A
authors.initials: RA
authors.lastname: Zucker
authors.forename: Marc A
authors.initials: MA
authors.lastname: Zimmerman
authors.forename: Brenda M
authors.initials: BM
authors.lastname: Booth
authors.forename: Frederic C
authors.initials: FC
authors.lastname: Blow
mesh_terms: D000293:Adolescent; D000428:Alcohol Drinking / Q000517:prevention & control; D002648:Child; D005260:Female; D006801:Humans; D007604:Juvenile Delinquency / Q000517:prevention & control; D008297:Male; D008385:Marijuana Smoking / Q000517:prevention & control*; D062405:Motivational Interviewing / Q000379:methods*; D011320:Primary Health Care; D013813:Therapy, Computer-Assisted; D016896:Treatment Outcome; D014481:United States; D014505:Urban Population
keywords: Adolescent; alcohol; brief intervention; cannabis; computerized; delinquency; drug; prevention; primary care; urban