title: Substance use and abuse in first-episode psychosis: prevalence before and after early intervention.
abstract: Despite the high prevalence of substance abuse among first-episode psychosis (FEP) populations, few studies examine whether early intervention (EI) improves substance abuse.
  
  
  OBJECTIVE
  To examine the prevalence and pattern of substance use and abuse among an FEP sample over 12 months.
  
  
  METHODS
  All the participants were diagnosed with a first episode of a schizophrenia spectrum disorder. The participants were followed prospectively. The prevalence rates of substance use and abuse from this sample were compared before and after 12 months of EI services and were compared with rates observed in a sample from the general population.
  
  
  RESULTS
  A total of 200 participants (80.0% males; mean age 24 years) entered the study: 183 participants completed all the assessments at baseline, 131 participants completed all the assessments at 12 months. At baseline, the findings showed similar prevalence rates between the FEP sample and the general sample for lifetime cannabis use (60% vs 55%, respectively) and hazardous alcohol use (26% vs 21%) but significantly different prevalence rates for lifetime hallucinogen (29% vs 15%; P < .001) and cocaine use (20% vs 14%; P < .001). At 12 months, the prevalence rates for drug abuse (P < .01), hazardous alcohol use (P < .01), and concurrent drug abuse and hazardous alcohol use (P < .05) were significantly lower than at baseline.
  
  
  CONCLUSIONS
  Substance use and abuse decreased significantly after 12 months of EI services; EI services may be able to detect and to reduce substance use among FEP patients before it becomes a more serious disorder.
authors.affiliation: Department of Psychiatry and Behavioural Neurosciences, Michael G. DeGroote School of Medicine, McMaster University, Hamilton, Ontario, Canada. archies@mcmaster.ca
authors.forename: Suzanne
authors.initials: S
authors.lastname: Archie
authors.forename: Brian R
authors.initials: BR
authors.lastname: Rush
authors.forename: Noori
authors.initials: N
authors.lastname: Akhtar-Danesh
authors.forename: Ross
authors.initials: R
authors.lastname: Norman
authors.forename: Ashok
authors.initials: A
authors.lastname: Malla
authors.forename: Paul
authors.initials: P
authors.lastname: Roy
authors.forename: Robert B
authors.initials: RB
authors.lastname: Zipursky
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011446:Prospective Studies; D011618:Psychotic Disorders / Q000453:epidemiology* / Q000534:rehabilitation*; D019966:Substance-Related Disorders / Q000453:epidemiology*; D013997:Time Factors