Cannabis use in first episode psychosis: what we have tried and why it hasn’t worked

Abstract

Background Up to 64% of individuals who have experienced a first episode of psychosis (FEP) have used cannabis, and 30% of these have a cannabis use disorder [1, 2]. Cannabis use among those with FEP is associated with negative outcomes (e.g., positive symptoms, illness severity) [1]. Given the relationship between cannabis use and psychosis, and the increasing availability of high potency tetrahydrocannabinol (THC) products, cannabis use prevention and treatment in people with FEP is a critical issue. Initial early intervention efforts that address cannabis and other substance use has been underwhelming. Early intervention programs for FEP generally include evidence-based practices focused on medication management, family psychoeducation, case management, individual therapy, and vocational services [3]. Brief or optional cognitive behavioral therapy for substance use is often integrated in early intervention programs. The question is, are these interventions sufficient in their intensity and/or duration to reduce cannabis use? The answer appears to be no. Young people enrolled in early intervention programs do not have lower levels of cannabis or other drug use than those who receive treatment as usual [4]. In a recent secondary data analysis, we found that frequent cannabis use (> 20 days per month) was higher in those randomized to the early intervention treatment than those in usual care [5]. These findings are consistent with the treatment outcomes of general cooccurring disorders. Few interventions for co-occurring disorders are designed to treat both schizophrenia spectrum and substance use disorders. Most are focused on improving psychiatric symptoms (e.g., assertive community treatment) or increasing drug or alcohol abstinence (e.g., contingency management). As a result, few interventions including contingency management (CM) consistently demonstrate reductions in both psychiatric symptoms and substance use [6]. Although the addition of CM or other evidence-based interventions to early intervention programs for FEP is appealing, truly integrative treatments are needed to improve the lives of young people living with psychosis and substance use disorders.