title: Patterns, predictors and impact of substance use in early psychosis: a longitudinal study.
abstract: OBJECTIVE
  The purpose was to determine the prevalence of substance use and its impact on outcome 3 years after presentation for a first-episode of psychosis.
  
  
  METHODS
  Subjects were 203 consecutive admissions to an early psychosis program. Assessments included substance use, positive, negative and depressive symptoms and social functioning. Assessments occurred at baseline, and 1-, 2- and 3-year follow-ups.
  
  
  RESULTS
  The prevalence of substance misuse was high with 51% having a substance use disorder (SUD), 33% with cannabis SUD and 35% with an alcohol SUD. Numbers with an alcohol SUD declined considerably by 1 year and for cannabis SUD by 2 years. Substance misuse was significantly associated with male gender, young age and age of onset and cannabis misuse with increased positive symptoms.
  
  
  CONCLUSIONS
  This study confirms the high rates of substance misuse, in particular cannabis, in first-episode psychosis. It further demonstrates that these rates can be reduced.
authors.affiliation: Department of Psychiatry, University of Toronto, Toronto, ON, Canada. jean_addington@camh.net
authors.forename: J
authors.initials: J
authors.lastname: Addington
authors.forename: D
authors.initials: D
authors.lastname: Addington
mesh_terms: D000328:Adult; D000416:Alberta; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007297:Inpatients; D008137:Longitudinal Studies; D008297:Male; D010045:Outpatients; D010352:Patient Dropouts / Q000706:statistics & numerical data; D011237:Predictive Value of Tests; D011618:Psychotic Disorders / Q000145:classification / Q000453:epidemiology / Q000523:psychology*; D012959:Socioeconomic Factors; D019966:Substance-Related Disorders / Q000145:classification / Q000523:psychology*; D014505:Urban Population