Use of Cannabidiol in the Management of Insomnia: A Systematic Review

Summary & key facts

This review looked at 34 studies that tested cannabidiol (CBD) for sleep problems. Some studies used mostly CBD and others used CBD with similar amounts of THC. Many studies reported that at least some participants had better sleep, but very few studies focused only on people with insomnia and most used weak or no objective measures. The authors say CBD alone or with equal THC may help, but better studies are needed before firm conclusions can be made.

Key facts:

• The review included 34 studies on CBD and sleep problems.
• All 34 studies reported improvement in insomnia symptoms for at least some participants.
• Nineteen of the 34 studies used CBD-predominant treatments; 21 used treatments with nearly equal ratios of CBD to THC (numbers come from the review).
• Among studies that did formal hypothesis testing, 4 of 7 CBD-predominant arms and 12 of 16 nearly equal CBD:THC arms reported statistically significant improvement in insomnia outcomes.
• Only 2 of the 34 studies specifically focused on patients with insomnia; one of those two was a case report.
• Many studies used nonvalidated subjective measures, and most studies did not include objective sleep measurements (for example, actigraphy or polysomnography), which limits confidence in the results.

Abstract

Background: Cannabidiol (CBD), one of the major cannabinoids derived from the cannabis plant, is available over the counter. CBD is often used by patients for the management of insomnia, yet research supporting CBDs effectiveness as a treatment for insomnia is inadequate. Objective: The objective of this review was to critically evaluate the literature regarding the therapeutic benefits of CBD in the management of insomnia. Methods: A comprehensive search of the following databases from inception to December 29, 2021, was conducted: Ovid MEDLINE® and Epub Ahead of Print, In-Process & Other Non-Indexed Citations and Daily, Ovid Embase, Ovid Cochrane Central Register of Controlled Trials, Ovid Cochrane Database of Systematic Reviews, and Scopus. The search included randomized controlled trials, nonrandomized experimental studies, cross-sectional studies, cohort studies, case series, and case reports. Risk of bias was assessed with the Agency for Healthcare Research and Quality design-specific recommended criteria. Results: Thirty-four studies were eligible for inclusion. All studies reported improvement in the insomnia symptoms of at least a portion of their participants. Of the 34 studies, 19 studies used CBD predominant therapy and 21 studies used nearly equal ratios of CBD to Δ9-tetrahydrocannabinol (THC). Of the studies that performed hypothesis testing, 4 of 7 studies with a CBD predominant arm and 12 of 16 studies with a nearly equal ratio of CBD to THC arm reported significant improvement in insomnia outcomes. However, only 2 of the 34 studies focused on patients with insomnia, of which 1 study was a case report. Additionally, several studies used nonvalidated subjective measures, and most studies failed to include objective measures for symptom assessment. Conclusions: The results of our systematic review suggest that CBD alone or with equal quantities of THC may be beneficial in alleviating the symptoms of insomnia. Nevertheless, future research assessing CBDs effectiveness in population of patients specifically with insomnia utilizing validated subjective and objective measures is necessary before definitive inferences can be made.

Topics

Cannabis and Cannabinoid Research Sleep and related disorders Sleep and Wakefulness Research

Categories

Health Sciences Medicine Pharmacology

Tags

Cannabidiol Cannabis Cochrane Library Insomnia Internal medicine Law Medicine MEDLINE Meta-analysis Political science Primary Insomnia Psychiatry Randomized controlled trial Sleep disorder Systematic review