Cannabis and stimulant disorders and readmission 2 years after first-episode psychosis.

Background: Few studies have examined the impact of stimulant use on outcome in early psychosis. Ceasing substance use may lead to positive outcomes in psychosis.

Aims: To examine whether baseline cannabis or stimulant disorders and ongoing drug use predict readmission within 2 years of a first psychosis admission.

Method: Predictors of readmission were examined with Cox regression in 7269 people aged 15-29 years with a first psychosis admission.

Results: Baseline cannabis and stimulant disorders did not predict readmission. A stimulant disorder diagnosis prior to index psychosis admission predicted readmission, but a prior cannabis disorder diagnosis did not. Ongoing problem drug use predicted readmission. The lowest rate of readmission occurred in people whose baseline drug problems were discontinued.

Conclusions: Prior admissions with stimulant disorder may be a negative prognostic sign in first-episode psychosis. Drug use diagnoses at baseline may be a good prognostic sign if they are identified and controlled.