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

Abstract

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. 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. 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. 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. 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.