Cannabidiol for moderate-severe insomnia: a randomized controlled pilot trial of 150 mg of nightly dosing.

STUDY OBJECTIVES:Low dose cannabidiol (CBD) has become readily available in numerous countries; however, little consensus exists on its efficacy as a sleep aid. This trial explored the efficacy of 150 mg of CBD (n=15) compared to placebo (n=15) as a sleep aid in primary insomnia. CBD supplementation was hypothesized to decrease insomnia symptoms and improve aspects of psychological health, relative to placebo. METHODS:Using a randomized, placebo-controlled parallel design featuring a single-blind placebo run-in week followed by a two-week double-blind randomized dosing phase, participants consumed the assigned treatment sublingually 60 minutes before bed nightly. Wrist-actigraphy and sleep diaries measured daily sleep. Sleep quality, sleep effort and well-being were measured weekly over four in-lab visits. Insomnia severity and trait anxiety were measured at screening and study conclusion. RESULTS:Insomnia severity, subjective sleep onset latency, sleep efficiency and wake after sleep onset did not differ between treatments throughout the trial (all p>0.05). Compared to placebo, the CBD group reported greater well-being scores throughout the trial (trial end mean difference=2.60, SE 1.20), transient elevated behavior following wakefulness scores after 1 week of treatment (mean difference=3.93, SE 1.53) and had superior objective sleep efficiency after 2 weeks of treatment (mean difference=6.85, SE 2.95) (all p<0.05). No other significant treatment effects were observed. CONCLUSIONS:Nightly supplementation of 150 mg CBD was similar to placebo regarding most sleep outcomes whilst sustaining greater well-being, suggesting more prominent psychological effects. Additional controlled trials examining varying treatment periods and doses are crucial. CLINICAL TRIAL REGISTRATION:Registry: Australian New Zealand Clinical Trials Registry; Title: Cannabidiol (CBD) treatment for insomnia; Identifier: ACTRN12620000070932; URL: https://anzctr.org.au/Trial/Registration/TrialReview.aspx?ACTRN=12620000070932.