Abstract
Persistent cannabis use among young adults with first episode psychosis (FEP), even those receiving early intervention services, has been associated with poor outcomes. In the United States (US), Coordinated Specialty Care (CSC) has been shown to be more effective at reducing symptoms, improving quality of life and increasing involvement in work or school, compared to typical care for FEP. However, little is known about the prevalence, course and outcomes for cannabis use in this real-world, clinical setting. This study examined the prevalence, course and outcomes of cannabis use categorized into three groups: no use, reduced use, and persistent use, among a sample of 938 CSC participants enrolled for at least 1 year. Prevalence of cannabis use was 38.8% at admission and 32.8% of the sample had persistent cannabis use at 1 year. At baseline, persistent cannabis users were more likely to be male (p < .001), white, non-Hispanic and black non-Hispanic (p = .001), have worse symptoms as measured by the GAF (p < .001), increased suicidality (p = .024), violent ideation (p = .008), and legal trouble (p = .006) compared with non-users. At 1 year, persistent users maintained worse symptoms compared with non-users (p = .021) while those who reduced use had significant improvement in symptoms compared with persistent users (p = .008). This study suggests that cannabis use is common among young adults enrolled in a CSC program in the US and that persistent cannabis users may have worse outcomes while reducing cannabis use may improve outcomes. These findings highlight the potential impact of secondary prevention in this population through reduction in cannabis use.