A pilot randomized controlled trial of a digital cannabis harm reduction intervention for young adults with first-episode psychosis who use cannabis

Cannabis use is widespread and associated with worsened prognosis for young adults with first-episode psychosis (FEP). Few cannabis harm reduction interventions have been evaluated for this population, despite potential to improve outcomes in those not ready for cannabis abstinence/reduction-focused interventions. This study aimed to determine a) the acceptability of a digital harm reduction intervention, the Cannabis Harm-reducing App to Manage Practices Safely (CHAMPS) and b) the feasibility of conducting a trial comparing FEP-specialized early intervention services (EIS)+CHAMPS versus EIS-only with this population. We conducted a multi-site pilot randomized controlled trial comparing both arms in 101 young adults (18 - 35 years old) with FEP using cannabis and attending EIS. Primary outcomes were trial retention rate (i.e., proportion of randomized participants retained at week 6; trial feasibility assessment) and CHAMPS completion rate (i.e., proportion of intervention participants completing four of six modules; CHAMPS acceptability assessment). Trial retention rate above 60 % indicated feasibility and completion rate above 50 % indicated acceptability. Additional outcomes included harm reduction strategy use, motivation to change cannabis behaviors, cannabis-related problems, cannabis use, psychotic symptoms and dependence severity, assessed at baseline, weeks 6, 12 and 18. Trial retention was 82.2 % and completion rate was 58.8 %, suggesting trial feasibility and CHAMPS acceptability. Signals of possible improvement in the intervention group were observed regarding harm reduction strategy use, motivation to change behaviors, cannabis-related problems and cannabis use frequency. This study supports conducting an efficacy trial assessing the potential of CHAMPS in improving outcomes for young adults with psychosis using cannabis.