medical cannabis and insomnia

A comprehensive Cochrane systematic review evaluated the efficacy and safety of medical cannabis for adults with primary or comorbid insomnia (1):

• included 9 randomized controlled trials (RCTs) comprising 537 adult participants (predominantly female, 72.7%)
• comparisons included medical cannabis versus placebo (8 trials) and medical cannabis versus the tricyclic antidepressant amitriptyline (1 trial)
• current evidence is of low-to-very-low certainty, indicating that medical cannabis has little to no clear, clinically meaningful benefit for insomnia, while increasing mild-to-moderate adverse events

Efficacy and Outcomes (Medical Cannabis vs Placebo)

• sleep quality / satisfaction: medical cannabis may result in little to no clinically meaningful improvement in sleep quality or satisfaction compared with placebo (standardized mean difference [SMD] -0.49, 95% confidence interval [CI] -1.06 to 0.08; 7 studies, 374 participants; very-low-certainty evidence)
• total sleep time (TST): resulted in no significant increase in total sleep time (mean difference ~8 minutes increase, 95% CI -23 to +38 minutes; 6 studies, 194 participants; very-low-certainty evidence)
• daytime functioning and quality of life: demonstrated very-low-certainty evidence with no clear demonstrable improvement across daytime performance or overall health-related quality of life metrics

Safety and Adverse Events

• incidence of adverse events: medical cannabis significantly increased the risk of experiencing adverse events compared with placebo (odds ratio [OR] 11.25, 95% CI 4.46 to 28.35; 3 crossover studies, 98 participants; low-certainty evidence)
• nature of adverse events: reported side effects were predominantly mild to moderate (e.g., somnolence, dizziness, dry mouth, cognitive sluggishness) with no serious adverse events reported in the pooled trials

Clinical Practice Implications

• evidence limitations: current clinical evidence is insufficient to support prescribing or recommending medical cannabis (including delta-9-tetrahydrocannabinol [THC] or cannabidiol [CBD] formulations) for insomnia due to high risk of bias, trial heterogeneity, small sample sizes, and imprecision
• first-line management: cognitive behavioral therapy for insomnia (CBT-I) remains the established, guideline-recommended first-line treatment for chronic insomnia disorder

Reference:

1. Varela LB, Miño Zambrano JE, Goncalves Costa BM, Silva GSM, Escobar Liquitay CM, Díaz Menai S, Meza N, Garegnani LI. Medical cannabis for the treatment of insomnia. Cochrane Database of Systematic Reviews. 2026, Issue 10. Art. No.: CD016216.