Cannabis abuse and the course of recent-onset schizophrenic disorders

Arch Gen Psychiatry. 1994 Apr;51(4):273-9. doi: 10.1001/archpsyc.1994.03950040017002.


Objective: We sought to examine the relation between cannabis abuse and the symptomatic course of recent-onset schizophrenia and related disorders.

Design: A prospective cohort study over a year using monthly Brief Psychiatric Rating Scale assessments.

Participants: Cannabis-abusing patients (n = 24) were compared with nonabusers (n = 69). Eleven patients were mild and 13 were heavy cannabis-abusing patients.

Results: Significantly more and earlier psychotic relapses occurred in the cannabis-abusing group (P = .03). This association became stronger when mild and heavy cannabis abuse were distinguished (P = .002). No confounding effect of other variables, eg, other street drugs, was found. In all but one patient, cannabis abuse preceded the onset of the first psychotic symptoms for at least 1 year.

Conclusions: Cannabis abuse and particularly heavy abuse can be considered a stressor eliciting relapse in patients with schizophrenia and related disorders and possibly a premorbid precipitant.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Ambulatory Care
  • Cohort Studies
  • Comorbidity
  • Female
  • Follow-Up Studies
  • Hospitalization
  • Humans
  • Male
  • Marijuana Abuse / complications
  • Marijuana Abuse / diagnosis*
  • Marijuana Abuse / epidemiology
  • Prognosis
  • Prospective Studies
  • Recurrence
  • Schizophrenia / diagnosis*
  • Schizophrenia / epidemiology
  • Schizophrenia / etiology
  • Schizophrenic Psychology