Effectiveness of cannabinoids on subjective sleep quality in people with and without insomnia or poor sleep: A systematic review and meta-analysis of randomised studies.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of randomized controlled trials
PubMed 40929927 · doi:10.1016/j.smrv.2025.102156
What was done
Authors conducted a systematic review and meta-analysis of randomized controlled trials identified from MEDLINE, Embase, and Cochrane databases comparing cannabinoids to placebo for subjective sleep quality in adults with or without insomnia or poor sleep. The primary outcome was self-reported sleep quality measured by standardized tools (PROMIS, PSQI, LSEQ, Sleep Diary). Secondary outcomes included actigraphy parameters, anxiety (GAD-7, STAI-T), well-being (WHO-5), and insomnia severity (ISI). Additional analyses evaluated participants with insomnia or poor sleep, as well as cannabidiol (CBD) versus non-CBD interventions.
What was found
Six trials involving 1,077 participants were included. Cannabinoids significantly improved sleep quality compared to placebo (SMD 0.53; 95% CI 0.03 to 1.02; p = 0.04; I² = 88%), with a similar effect in those with baseline insomnia or poor sleep (SMD 0.60; 95% CI 0.09 to 1.11; p = 0.02; I² = 89%). Non-CBD cannabinoids demonstrated significant efficacy (SMD 0.82; 95% CI 0.24 to 1.40; p = 0.005), whereas CBD-only therapies showed no significant effect (SMD 0.13; 95% CI -0.38 to 0.65; p = 0.61). Quantitative results for secondary outcomes (actigraphy, anxiety, well-being, insomnia severity) were not reported in the abstract.
Why it matters
This review distinguishes between cannabinoid formulations, showing that subjective sleep quality improvements are driven by non-CBD formulations rather than CBD alone, helping guide clinical use and future trial design.
Limits
The total evidence base is small, comprising only 6 trials. Extreme statistical heterogeneity was present across analyses (I² = 88% to 89%). The abstract omits results for objective actigraphy and secondary endpoints, and does not report specific cannabinoid doses, formulations, safety, or treatment durations.
Cited by
- supports Scientific studies on CBD and sleep show mixed results, with roughly half showing benefits and the other half showing no effect or worsened sleep.