Project 462127

Psychotic disorders (PD) are characterized by a loss of contact with reality. In Canada, their annual economic burden is at least 10 billion dollars. Cannabis use is one of the key factors leading to psychiatric re-hospitalization in PD. In these populations, cannabis use is also associated with depressive symptoms, medication non-compliance, hostility as well as reduced quality of life. Unfortunately, there is no evidence-based intervention available for the treatment of cannabis use disorder (CUD) in this population. Novel interventions for CUD are thus critically needed. Virtual reality (VR) based therapies are a promising avenue that allow patients to try novel strategies in real time instead of having to learn abstract rules. To fill a clinical need, our team has created a distinctive intervention for CUD in patients with PD. VR Therapy (VRT) displays strong experiential and relational components that are crucially missing in conventional interventions. This proposal thus aims to conduct a single-blind randomized controlled trial to verify whether VRT has greater efficacity over Supportive Therapy on several outcomes, including reductions in cannabis use and CUD severity, and increased quality of life. We will also explore whether the greater improvements attributable to VRT persist in time, and perform analyses on sex/gender, motivation to change cannabis habits, psychotic relapses, and THC metabolite levels. Noteworthily, cannabis-related hospitalizations have been identified as one of the core indicators to measure the success of cannabis legalization. As a result, there is a pressing need to design innovative interventions that could have a significant impact on this costly and prime outcome. As there is no evidence-based therapeutic options for CUD in patients with PD, the current trial will contribute to the validation of a novel approach and create new therapeutic possibilities.