Mobile Application-Based Interventions for Cannabis Use in Young Adults With First Episode Psychosis

Psychotic disorders affect approximately 4% of Canadians and have a significant impact on individuals' well-being, their families and social networks, and healthcare systems. The development of psychosis is explained by a complex interplay of genetic and environmental factors, including the use of psychoactive substances. Frequent cannabis use can contribute to the development of psychotic disorders. The prevalence of cannabis use disorder (CUD) in individuals with a first-episode psychosis (FEP) followed in Early Intervention Services (EIS) is 42-53%, well above that of the general population (\~3%). Cannabis use in individuals with psychosis is associated with increased symptom severity, higher rates of relapse and hospitalization, and poor psychosocial functioning. Standardized mobile app-based interventions offer a scalable and accessible solution. Our team developed and piloted CHAMPS (harm reduction) and iCanChange (use reduction/cessation) with favourable results: retention 82% (CHAMPS) and 84-86% (iCC), high satisfaction, and preliminary efficacy signals. The two pilot studies were targeting feasibility, this study is studying efficacy of the two app-based interventions (CHAMPS and iCanChange).