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

The takeaway

Adults who reduced their cannabis use over 12 weeks showed improvements in anxiety, depression, and sleep quality, but their overall quality of life did not significantly change.

Read this if you use cannabis regularly and experience anxiety, depression, or sleep problems and want to know if cutting back might help.

Cannabis reduction improved anxiety, depression, and sleep but not overall quality of life

What the researchers found

This study tracked 302 adults with cannabis use disorder over 12 weeks of a medication trial, splitting them into those whose cannabis use decreased and those whose use increased.

The cannabis reduction group (152 people) showed statistically significant improvements in anxiety, depression, and sleep quality compared to the cannabis increase group (150 people), even after controlling for demographics, treatment condition, and concurrent tobacco and alcohol use.

However, reductions in cannabis use did not translate into improved overall quality of life. This disconnect suggests that while reducing cannabis use alleviates specific psychiatric symptoms, broader life satisfaction may depend on other factors not addressed by cannabis reduction alone.

The findings held up after accounting for other substance use, meaning the improvements were specifically linked to changes in cannabis use rather than general behavioral changes.

Why it matters

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.

The numbers in context

302 adults over 12 weeks. Cannabis Use Reduction group: n=152. Cannabis Use Increase group: n=150. Significant improvements in anxiety (beta=-0.09, p<0.05), depression (beta=-0.11, p<0.01), and sleep quality (beta=-0.07, p<0.05). No change in quality of life.

How the study worked

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.

What this study cannot tell us

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.

How to read the evidence

Longitudinal analysis with statistical controls for confounders. Moderate because it is a secondary analysis of a treatment trial with a relatively short follow-up period.

When this study was published

Published in 2017.

The bigger picture

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.

Questions still open

Would quality of life improve with longer follow-up after cannabis reduction? Do the anxiety and sleep improvements persist beyond 12 weeks, or do they plateau? Would similar improvements be seen in recreational users who reduce use, or only in those with cannabis use disorder?

Common questions

Does quitting cannabis improve mental health?

This study found that reducing cannabis use over 12 weeks was associated with improvements in anxiety, depression, and sleep quality. However, overall quality of life did not change, suggesting that mental health improvement is just one piece of the puzzle.

Can cannabis cause anxiety and depression?

This study cannot prove causation, but it showed that when the same individuals reduced their cannabis use, their anxiety and depression symptoms improved. This longitudinal pattern is consistent with cannabis contributing to these symptoms, though other explanations remain possible.

Read the original research

Reductions in cannabis use are associated with improvements in anxiety, depression, and sleep quality, but not quality of life.

Journal of substance abuse treatment, 81, 53-58

View on PubMed ↗Publisher’s paper ↗

Citation

Hser, Yih-Ing; Mooney, Larissa J; Huang, David; Zhu, Yuhui; Tomko, Rachel L; McClure, Erin; Chou, Chih-Ping; Gray, Kevin M. (2017). Reductions in cannabis use are associated with improvements in anxiety, depression, and sleep quality, but not quality of life.. Journal of substance abuse treatment, 81, 53-58. https://doi.org/10.1016/j.jsat.2017.07.012