title: Differences in prevalence and patterns of substance use in schizophrenia and bipolar disorder.
abstract: BACKGROUND
  Schizophrenia and bipolar disorder have partly overlapping clinical profiles, which include an over-representation of substance-use behaviour. There are few previous studies directly comparing substance-use patterns in the two disorders. The objective of the present study was to compare the prevalence of substance use in schizophrenia and bipolar disorder, and investigate possible differences in pattern and frequency of use.
  
  
  METHODS
  A total of 336 patients with schizophrenia or bipolar spectrum disorder from a catchment area-based hospital service were included in a cross-sectional study. In addition to thorough clinical assessments, patients were interviewed about drug-use history, habits and patterns of use. The prevalence and drug-use patterns were compared between groups.
  
  
  RESULTS
  Patients with bipolar disorder had higher rates of alcohol consumption, while schizophrenia patients more often used centrally stimulating substances, had more frequent use of non-alcoholic drugs and more often used more than one non-alcoholic drug. Single use of cannabis was more frequent in bipolar disorder.
  
  
  CONCLUSIONS
  The present study showed diagnosis-specific patterns of substance use in severe mental disorder. This suggests a need for more disease-specific treatment strategies, and indicates that substance use may be an important factor in studies of overlapping disease mechanisms.
authors: Institute of Psychiatry, Medical Faculty, University of Oslo, Oslo, Norway. p.a.ringen@medisin.uio.no
authors: P A
authors: PA
authors: Ringen
authors: T V
authors: TV
authors: Lagerberg
authors: A B
authors: AB
authors: Birkenaes
authors: J
authors: J
authors: Engn
authors: A
authors: A
authors: Faerden
authors: H
authors: H
authors: Jónsdottir
authors: R
authors: R
authors: Nesvåg
authors: S
authors: S
authors: Friis
authors: S
authors: S
authors: Opjordsmoen
authors: F
authors: F
authors: Larsen
authors: I
authors: I
authors: Melle
authors: O A
authors: OA
authors: Andreassen
mesh_terms: D000328:Adult; D017677:Age Distribution; D001714:Bipolar Disorder / Q000453:epidemiology* / Q000523:psychology*; D002391:Catchment Area, Health / Q000706:statistics & numerical data; D015897:Comorbidity; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007406:Interview, Psychological / Q000379:methods; D008297:Male; D009664:Norway / Q000453:epidemiology; D015995:Prevalence; D011569:Psychiatric Status Rating Scales; D012559:Schizophrenia / Q000453:epidemiology*; D012565:Schizophrenic Psychology; D017678:Sex Distribution; D019966:Substance-Related Disorders / Q000453:epidemiology* / Q000523:psychology*