300mg CBD Shows Promise for Sleep in Worriers — But Doesn't Beat Placebo
In high-worry individuals, 300 mg CBD daily for two weeks improved sleep significantly more than 50 mg CBD, but did not significantly outperform placebo, leaving CBD's sleep benefits unconfirmed.
Quick Facts
What This Study Found
300 mg CBD decreased sleep disturbances significantly more than 50 mg CBD (B=-0.39, t=-2.59, p<0.05, d=0.08) but not significantly more than placebo (B=-0.32, t=-2.09, p=0.10, d=0.07), with no effects on sedation or cognitive impairment.
Key Numbers
n=63; mean age 29.27; 300 mg vs 50 mg CBD significant (p<0.05, d=0.08); 300 mg vs placebo not significant (p=0.10, d=0.07); 2-week treatment; no sedation effects; no cognitive impairment
How They Did This
Randomized, double-blind, placebo-controlled trial with 63 individuals reporting elevated trait worry, assigned to 300 mg CBD, 50 mg CBD, or placebo daily for 2 weeks, measuring sleep disturbances, sleep quality, sedation, and cognitive function.
Why This Research Matters
Despite massive consumer interest in CBD for sleep, this rigorous trial found that CBD beat a lower dose but couldn't clearly beat placebo — highlighting the gap between marketing claims and evidence.
The Bigger Picture
The inability of 300 mg CBD to significantly outperform placebo for sleep underscores how little rigorous evidence supports the massive CBD-for-sleep consumer market.
What This Study Doesn't Tell Us
Small sample (n=63); very small effect sizes (d=0.07-0.08); only 2-week duration; self-report sleep measures; trait worry sample may not generalize; only two CBD doses tested; borderline p-value vs. placebo suggests possible underpowering.
Questions This Raises
- ?Would a larger sample reveal a significant placebo comparison?
- ?Would higher doses or longer treatment show clearer effects?
- ?Is the sleep benefit mediated by anxiety reduction rather than direct sleep effects?
Trust & Context
- Key Stat:
- Evidence Grade:
- Well-designed RCT but underpowered (n=63) with very small effect sizes, yielding inconclusive results for the primary comparison against placebo.
- Study Age:
- Published 2026; represents latest clinical evidence on CBD and sleep.
- Original Title:
- The effects of cannabidiol on sleep disturbances within a sample of high trait worriers: A double-blind, randomized placebo controlled trial.
- Published In:
- Experimental and clinical psychopharmacology (2026)
- Authors:
- Gournay, L Riley(3), Ferretti, Morgan L(2), Dickens, Harrison B, Floyd, Veronica, Fernandez, Daniella A, Rathbun, Ezri, Nguyen, Anna-Marie, Leen-Feldner, Ellen W
- Database ID:
- RTHC-08293
Evidence Hierarchy
Frequently Asked Questions
Does CBD help you sleep?
This trial found that 300 mg daily CBD improved sleep more than 50 mg CBD in people with high worry, but the improvement was not significantly better than placebo — meaning the evidence remains inconclusive.
What dose of CBD is needed for sleep?
300 mg outperformed 50 mg in this study, but neither dose clearly beat placebo for sleep outcomes, suggesting that if CBD has sleep benefits, they may require higher doses or longer treatment periods to demonstrate.
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Cite This Study
https://rethinkthc.com/research/RTHC-08293APA
Gournay, L Riley; Ferretti, Morgan L; Dickens, Harrison B; Floyd, Veronica; Fernandez, Daniella A; Rathbun, Ezri; Nguyen, Anna-Marie; Leen-Feldner, Ellen W. (2026). The effects of cannabidiol on sleep disturbances within a sample of high trait worriers: A double-blind, randomized placebo controlled trial.. Experimental and clinical psychopharmacology. https://doi.org/10.1037/pha0000832
MLA
Gournay, L Riley, et al. "The effects of cannabidiol on sleep disturbances within a sample of high trait worriers: A double-blind, randomized placebo controlled trial.." Experimental and clinical psychopharmacology, 2026. https://doi.org/10.1037/pha0000832
RethinkTHC
RethinkTHC Research Database. "The effects of cannabidiol on sleep disturbances within a sa..." RTHC-08293. Retrieved from https://rethinkthc.com/research/gournay-2026-the-effects-of-cannabidiol
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.