title: Naturalistic follow-up of co-morbid substance use in schizophrenia: the West London first-episode study.
abstract: BACKGROUND
  The impact of co-morbid substance use in first-episode schizophrenia has not been fully explored.
  
  
  METHODS
  This naturalistic follow-up of a cohort of 152 people with first-episode schizophrenia examined substance use and clinical outcome in terms of symptoms and social and neuropsychological function.
  
  
  RESULTS
  Data were collected on 85 (56%) of the patient cohort after a median period of 14 months. Over the follow-up period, the proportion of smokers rose from 60% at baseline to 64%. While 30% reported lifetime problem drinking of alcohol at baseline, only 15% had problem drinking at follow-up. Furthermore, while at baseline 63% reported lifetime cannabis use and 32% were currently using the drug, by the follow-up assessment the latter figure had fallen to 18.5%. At follow-up, persistent substance users had significantly more severe positive and depressive symptoms and greater overall severity of illness. A report of no lifetime substance use at baseline was associated with greater improvement in spatial working memory (SWM) at follow-up.
  
  
  CONCLUSIONS
  Past substance use may impede recovery of SWM performance in people with schizophrenia in the year or so following first presentation to psychiatric services. The prevalence of substance use other than tobacco tends to diminish over this period, in the absence of specific interventions. Persistent substance use in first-episode schizophrenia is associated with more severe positive and depressive symptoms but not negative symptoms, and should be a target for specific treatment intervention.
authors.affiliation: Department of Psychological Medicine, Imperial College Faculty of Medicine, London, UK.
authors.forename: I
authors.initials: I
authors.lastname: Harrison
authors.forename: E M
authors.initials: EM
authors.lastname: Joyce
authors.forename: S H
authors.initials: SH
authors.lastname: Mutsatsa
authors.forename: S B
authors.initials: SB
authors.lastname: Hutton
authors.forename: V
authors.initials: V
authors.lastname: Huddy
authors.forename: M
authors.initials: M
authors.lastname: Kapasi
authors.forename: T R E
authors.initials: TR
authors.lastname: Barnes
mesh_terms: D000328:Adult; D019973:Alcohol-Related Disorders / Q000175:diagnosis / Q000453:epidemiology; D015331:Cohort Studies; D015897:Comorbidity; D003866:Depressive Disorder / Q000175:diagnosis / Q000453:epidemiology; D017831:Diagnosis, Dual (Psychiatry); D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008131:London / Q000453:epidemiology; D008297:Male; D002189:Marijuana Abuse / Q000175:diagnosis / Q000453:epidemiology; D009483:Neuropsychological Tests / Q000706:statistics & numerical data; D015995:Prevalence; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data; D012559:Schizophrenia / Q000175:diagnosis / Q000453:epidemiology*; D012720:Severity of Illness Index; D012917:Social Adjustment; D019966:Substance-Related Disorders / Q000175:diagnosis / Q000453:epidemiology*; D014029:Tobacco Use Disorder / Q000175:diagnosis / Q000453:epidemiology