Virtual reality avatar therapy reduced cannabis use in patients with severe mental disorders, with effects lasting 12 months

Significant reductions in cannabis quantity were maintained through 12-month follow-up (d=0.804, p<0.001), confirmed by urine quantification. Use frequency showed a small significant reduction at 3 months (d=0.384, p=0.03). Improvements were also seen in CUD severity, cannabis-related negative consequences, motivation to change, harm-mitigation strategies, quality of life, and psychiatric symptoms.

Single-arm pilot clinical trial with 32 participants having dual CUD and severe mental disorder. 8 intervention sessions where participants dialogued in VR with an avatar representing a person significant to their cannabis use, animated by a therapist. Assessments before intervention and at post, 3, 6, and 12 months.

Current psychotherapeutic treatments for CUD in severe mental illness have limited effectiveness. This innovative approach uses VR to create a safe space for patients to practice conversations about their cannabis use, showing promising and durable results in a notoriously difficult-to-treat population.

If VR avatar therapy can reduce cannabis use in people with severe mental illness where other approaches have failed, it could represent a new treatment paradigm. The approach is being tested in a randomized controlled trial.

Single-arm design without control group. 32 participants. Cannot separate VR-specific effects from general therapeutic contact. May not be scalable or accessible in all clinical settings. Selection bias from voluntary participation.