title: Substance misuse and early psychosis.
abstract: OBJECTIVE
  This paper sought to review current knowledge about the relationship between substance misuse and early psychosis.
  
  
  METHODS
  A literature search was conducted using Medline and restricting the search to articles after 1996. Additional articles were sourced from reference lists of relevant articles.
  
  
  RESULTS
  There is a high prevalence of substance misuse among persons with early psychosis, with cannabis and alcohol featuring prominently. Substance misuse is associated with earlier onset and possibly more positive symptoms, although apparently not with greater cognitive impairment. Cannabis appears to confer an increased likelihood of developing schizophrenia in biologically vulnerable individuals. Amphetamines also cause psychosis which may become chronic, although specific vulnerability to this effect is less well established. Many cases of so-called 'drug-induced psychosis' become diagnosed as schizophrenia in later years. Specific intervention programs report positive outcomes with regard to substance misuse and the course of psychosis.
  
  
  CONCLUSIONS
  Substance misuse should always be assessed in this patient group, bearing in mind the potential interactive causes of psychopathology. Intervention is of value in improving outcomes.
authors.affiliation: Mental Health (East), Sydney West Area Health Service, NSW, Australia. peter_tucker@wsahs.nsw.gov.au
authors.forename: Peter
authors.initials: P
authors.lastname: Tucker
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000428:Alcohol Drinking / Q000453:epidemiology / Q000523:psychology; D019969:Amphetamine-Related Disorders / Q000453:epidemiology / Q000523:psychology; D003072:Cognition Disorders / Q000453:epidemiology / Q000523:psychology; D006801:Humans; D002189:Marijuana Abuse / Q000453:epidemiology / Q000523:psychology; D008694:Methamphetamine; D011605:Psychoses, Substance-Induced / Q000453:epidemiology; D011618:Psychotic Disorders / Q000453:epidemiology*; D019966:Substance-Related Disorders / Q000453:epidemiology*; D055815:Young Adult
chemical_list: D008694:Methamphetamine