Cannabis-induced psychosis: a cross-sectional comparison with acute schizophrenia

Acta Psychiatr Scand. 2002 Mar;105(3):173-8. doi: 10.1034/j.1600-0447.2002.1o079.x.


Objective: The existence of cannabis-induced psychosis (CP) remains controversial, partly because of methodological problems. We hypothesize that acute schizophrenia (AS) and CP can have distinct demographic, premorbid and clinical features.

Method: We compared 26 patients with CP to 35 with AS, after their cannabis-consumption status was confirmed by repeated urine screens. Patients with CP were assessed after at least 1 week but not more than 1 month of abstinence. Symptoms were evaluated with the Present State Examination (PSE).

Results: In group CP, male gender, expansive mood and ideation, derealization/depersonalization, visual hallucinations, and disturbances of sensorium were more frequent than in group AS. Premorbid schizoid personality traits were more frequently associated to AS and antisocial personality traits to CP.

Conclusion: The continuous heavy use of cannabis can induce a psychotic disorder distinct from AS. These two clinical entities share some features but they differ in others.

Publication types

  • Comparative Study

MeSH terms

  • Acute Disease
  • Adult
  • Cannabis / adverse effects*
  • Cross-Sectional Studies
  • Female
  • Humans
  • Male
  • Marijuana Abuse / complications*
  • Marijuana Abuse / urine
  • Personality
  • Psychiatric Status Rating Scales
  • Psychoses, Substance-Induced / epidemiology
  • Psychoses, Substance-Induced / etiology*
  • Psychoses, Substance-Induced / urine
  • Schizophrenia / diagnosis*
  • Schizophrenia / epidemiology
  • Schizophrenia / urine