Linares · Frontiers in pharmacology 2018 · randomized, double-blind, placebo-controlled crossover trial · n=26

No Acute Effects of Cannabidiol on the Sleep-Wake Cycle of Healthy Subjects: A Randomized, Double-Blind, Placebo-Controlled, Crossover Study.

Cited 100 times in the scientific literature.

Level 2 - randomized trial

Individual randomized, double-blind, placebo-controlled crossover trial

PubMed 29674967 · doi:10.3389/fphar.2018.00315 · record verified 2026-08-31

What was done

In a randomized, double-blind, placebo-controlled crossover trial, 27 healthy volunteers (1 withdrew, resulting in 26 completers) received a single oral dose of cannabidiol (CBD, 300 mg) or placebo across two separate nights. The intervention was administered 30 minutes prior to an 8-hour polysomnography recording. Subjective and cognitive measures were completed immediately after polysomnography to evaluate residual effects.

What was found

The authors reported no statistically significant differences between CBD and placebo across sleep architecture or next-day cognitive and subjective parameters (p > 0.05). No specific numerical values, means, or effect sizes were reported in the abstract.

Why it matters

Unlike several conventional anxiolytic or antidepressant medications such as benzodiazepines and SSRIs, an acute 300 mg dose of CBD does not appear to disrupt baseline sleep architecture in healthy adults.

Limits

The sample size was small (n = 26) and limited to healthy volunteers without sleep or psychiatric disorders. Only a single acute dose of 300 mg was tested; chronic dosing, alternative dose levels, and clinical populations were not evaluated.

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