Reducing Cannabis Use Improved Anxiety, Depression, and Sleep But Not Overall Quality of Life

Secondary analysis of a 12-week cannabis use disorder medication trial with 302 adults (ages 18-50). Participants were classified into Cannabis Use Reduction (n=152) and Cannabis Use Increase (n=150) groups based on individual use trajectories. Latent growth curve models examined associations between use changes and changes in anxiety, depression, sleep quality, and quality of life, controlling for demographics and concurrent substance use.

This is one of the few studies to demonstrate a longitudinal relationship between changes in cannabis use and changes in mental health symptoms within the same individuals over time. The specificity of symptom improvement (anxiety, depression, sleep but not quality of life) provides nuanced evidence for clinical conversations about what reducing cannabis use can and cannot achieve.

These findings suggest that cannabis use may contribute to anxiety, depression, and sleep problems, and that these symptoms are at least partially reversible with use reduction. The null finding on quality of life indicates that cannabis-related psychiatric symptoms are just one component of overall wellbeing.

Secondary analysis of a treatment trial, so participants were already seeking to reduce use. The 12-week observation period may be too short to detect quality-of-life changes. Participants had cannabis use disorder, so findings may not apply to casual users. The direction of causality cannot be fully established.