Use of Cannabidiol in the Management of Insomnia: A Systematic Review.
Level 2 - randomized trial
Systematic review of heterogeneous study designs including observational studies, case series, and case reports rather than exclusively RCTs
PubMed 36149724 · doi:10.1089/can.2022.0122
What was done
Authors conducted a systematic review searching MEDLINE, Embase, Cochrane CENTRAL, Cochrane Database of Systematic Reviews, and Scopus from inception to December 29, 2021. The search included randomized controlled trials, nonrandomized experimental studies, cohort studies, cross-sectional studies, case series, and case reports evaluating cannabidiol (CBD) for insomnia. Risk of bias was evaluated using Agency for Healthcare Research and Quality design-specific criteria.
What was found
Thirty-four studies met inclusion criteria, and all reported insomnia symptom improvement in at least some participants. CBD-predominant therapy was used in 19 studies, and nearly equal CBD to delta-9-tetrahydrocannabinol (THC) ratios were used in 21 studies. Among studies performing hypothesis testing, 4 of 7 CBD-predominant studies and 12 of 16 balanced CBD:THC studies reported statistically significant insomnia improvement. However, only 2 of the 34 included studies evaluated patients diagnosed with insomnia (one of which was a single case report).
Why it matters
Despite widespread over-the-counter use of CBD for sleep disturbances, high-quality clinical evidence directly evaluating CBD in clinical insomnia populations remains minimal.
Limits
Only two studies specifically enrolled patients with insomnia, one being a single case report. The included body of literature largely relied on nonvalidated subjective measures, lacked objective sleep metrics, included uncontrolled designs, and frequently co-administered THC.
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.