Non-CBD Cannabinoids May Improve Sleep Quality

Non-cannabidiol (CBD) cannabinoids are associated with improvements in sleep quality, according to results of a systematic review and meta-analysis published in Sleep Medicine Reviews.

Researchers systematically searched publication databases through May 2024 to evaluate the effects of cannabinoids on sleep in adults with and without insomnia or poor sleep. The review included 6 randomized controlled trials involving 1077 participants, whose conditions ranged from chronic insomnia and self-reported clinical insomnia to poor sleep quality, moderate to severe insomnia, or healthy sleep. Mean participant ages ranged from 25.9 to 53 years, and the proportion of women ranged from 50% to 80.3%. Overall, 67.3% of participants were randomly assigned to receive a cannabinoid medication.

Compared with placebo, cannabinoid therapy was associated with significant improvements in subjective sleep quality (standardized mean difference [SMD], 0.53; 95% CI, 0.03-1.02; I², 88%; P =.04).

[T]he results are encouraging and provide support for further investigation of cannabinoid therapies for the treatment of poor sleep.

Cannabinoid therapies did not significantly affect:

• Actigraphy-assessed number of awakenings (SMD, -0.07; 95% CI, -0.45 to 0.31; I², 0%; P =.72)
• Sleep onset latency (SMD, -0.26; 95% CI, -0.64 to 0.13; I², 0%; P =.19)
• Wake after sleep onset (SMD, -0.29; 95% CI, -0.67 to 0.10; I², 0%; P =.15)
• Sleep efficiency (SMD, 0.22; 95% CI, -0.54 to 0.97; I², 72%; P =.57)
• Total sleep time (SMD, 0.34; 95% CI, -0.41 to 1.10; I², 72%; P =.37)
• Insomnia symptoms (mean difference [MD], -2.38; 95% CI, -6.64 to 1.88; I², 84%; P =.27)
• Anxiety (SMD, -0.26; 95% CI, -0.95 to 0.43; I², 79%; P =.46)
• Well-being (MD, 1.36; 95% CI, -0.41 to 3.14; I², 70%; P =.13)

In a leave-one-out sensitivity analysis, removal of individual studies revealed significant effects of cannabinoids on:

• Actigraphy-measured total sleep time (SMD, 0.71; 95% CI, 0.18-1.23; I², 21%; P =.008)
• Actigraphy-measured sleep efficiency (SMD, 0.60; 95% CI, 0.14-1.06; I², 0%; P =.01)
• Insomnia symptoms (MD, -4.56; 95% CI, -6.60 to -2.52; I², 0%; P <.0001)
• Anxiety (SMD, -0.68; 95% CI, -0.84 to -0.51; I², 0%; P <.00001)

In subgroup analyses, improvements in sleep quality were observed with non-CBD interventions (SMD, 0.68; 95% CI, 0.12-1.25; I², 91%; P =.02) but not with CBD-only interventions (SMD, 0.13; 95% CI, -0.38 to 0.65; I², 0%; P =.61).

In additional sensitivity analyses, cannabinoids significantly improved sleep quality when participants with healthy sleep at baseline were excluded (SMD, 0.60; 95% CI, 0.09-1.11; I², 89%; P =.02). However, when crossover trials were excluded, the effect was not significant (SMD, 0.45; 95% CI, -0.16 to 1.05; I², 91%; P =.15).

Study limitations include heterogeneity and limited quality of available data, as the removal of a single study altered the significance of key outcomes.

The study authors concluded, “The variability in effects across studies and uncertainties highlighted in the sensitivity analyses suggest these findings should be interpreted with some caution. However, the results are encouraging and provide support for further investigation of cannabinoid therapies for the treatment of poor sleep.”