Cannabis Use and Symptomatic Relapse in First Episode Schizophrenia: Trigger or Consequence? Data from the OPTIMISE Study

Abstract

Background and Hypothesis: This analysis examined the relationship between cannabis use, compliance with antipsychotics and risk for relapse in patients in remission following a first episode of schizophrenia, schizophreniform, or schizoaffective disorder. Study Design: Analyses were performed on data from a large European study on first episode of schizophrenia, schizophreniform, or schizoaffective disorder (OPTiMiSE). After 10 weeks of antipsychotic treatment, 282/446 patients (63%) met criteria for symptomatic remission; of whom 134/282 (47.5%) then completed a 1-year follow-up. Cross-lagged models and mediation models investigated the temporal relationships between cannabis use, compliance with antipsychotics, social functioning, and symptomatic worsening/relapse. Study Results: Compared to nonusers, cannabis use increased risk for relapse, adjusted hazard ratio (HR)=3.03 (SE=0.32), P