Expanding the toolbox of interventions for cannabis use disorder in individuals with first-episode psychosis: A pilot randomized controlled trial of iCanChange (iCC), a novel app-based psychological intervention.

Delivering face-to-face psychological interventions for cannabis use disorder (CUD) in early intervention services (EIS) for psychosis is often limited by structural barriers. App-based interventions may help overcome these limitations, though studies in non-psychosis populations report low engagement and retention. This study evaluated the feasibility of conducting an efficacy randomized controlled trial (RCT) of iCanChange (iCC), a novel app-based psychological intervention for CUD, and explored preliminary effects on cannabis use and related outcomes. We conducted a pilot RCT across 6 EIS programs in Canada, with 101 young adults aged 18-35 years with first-episode psychosis and CUD. They were randomized to modified EIS plus iCC (n = 51) or EIS only (n = 50). The intervention lasted 12 weeks with assessments at baseline and weeks 6, 12 (primary endpoint), and 24. Primary feasibility outcomes were intervention acceptability, defined as iCC completion (>50% of participants completing >50% modules), and trial retention, defined as >50% of participants retained at week 12. Secondary outcomes included cannabis use quantity and frequency, participant satisfaction, and app use metrics. Exploratory outcomes included cannabis-related outcomes, psychotic symptoms, and life satisfaction. Retention at week 12 was 84% in the intervention group and 86% in the control group, while iCC completion rate was 49% in intent-to-treat and 54% in per-protocol analyses. Preliminary signals of improvement in the intervention group were observed regarding cannabis use frequency, cannabis-related problems, dependence severity, and coping self-efficacy. Results demonstrate strong retention, supporting the feasibility of an efficacy trial while highlighting the need to enhance app engagement in youth with psychosis.