Acute Effects of Oral Cannabinoids on Sleep and High-Density EEG in Insomnia: A Pilot Randomised Controlled Trial.
Level 2 - randomized trial
Individual randomized controlled trial
PubMed 40631525 · doi:10.1111/jsr.70124
What was done
In a pilot randomized controlled trial, 20 adults with DSM-5 diagnosed insomnia disorder (16 female, mean age 46.1 years) received either a single oral dose containing 10 mg THC and 200 mg CBD (THC/CBD) or placebo. Objective sleep outcomes and regional brain activity were assessed using 256-channel high-density EEG. Next-day assessments included objective alertness, subjective sleepiness, subjective sleep quality, cognitive performance, and simulated driving performance evaluated at least 9 hours post-treatment.
What was found
Compared to placebo, THC/CBD decreased total sleep time (-24.5 min, p = 0.05, d = -0.5) with no significant change in wake after sleep onset (+10.7 min, p > 0.05). THC/CBD significantly decreased REM sleep time (-33.9 min, p < 0.001, d = -1.5) and increased REM latency (+65.6 min, p = 0.008, d = 0.7). High-density EEG showed regional decreases in N2 gamma and N3 delta activity, with regional increases in REM beta and alpha activity. The next day, self-reported sleepiness showed a small increase (+0.42 points, p = 0.02, d = 0.22), with no observed changes in objective alertness, subjective sleep quality, cognitive performance, or simulated driving performance.
Why it matters
This study shows that an acute combination of THC and CBD alters sleep architecture primarily by suppressing REM sleep and reducing total sleep time, while producing no detectable next-day driving or cognitive deficits.
Limits
The study is limited by a small pilot sample size (n = 20), testing only a single acute dose of a fixed THC/CBD ratio, which precludes conclusions about chronic use, individual cannabinoid contributions, or dose-dependent effects.
Cited by
- supports THC is a potent suppressor of REM sleep in many individuals.