Systematic review found insufficient evidence for cannabinoids as sleep treatments, but promising leads for several disorders | Research

The takeaway

A systematic review of 14 preclinical and 12 clinical studies found insufficient evidence to support routine use of cannabinoids for sleep disorders, but identified promising preliminary evidence for sleep apnea, insomnia, and PTSD-related nightmares.

Sleep medicine clinicians, patients using cannabis for sleep, and cannabinoid researchers.

Insufficient evidence for routine use; promising leads for 6 sleep disorders

What the researchers found

Across 26 studies (14 preclinical, 12 clinical), evidence was insufficient for routine clinical use of cannabinoids for any sleep disorder due to limited research and moderate-to-high risk of bias. However, promising preliminary evidence was identified for sleep apnea, insomnia, PTSD-related nightmares, restless legs syndrome, REM sleep behavior disorder, and narcolepsy.

Why it matters

Cannabis is one of the most commonly cited reasons people use for sleep improvement, but this systematic review shows the clinical evidence does not yet support this popular use. The gap between public perception and evidence is stark.

The numbers in context

14 preclinical + 12 clinical studies met criteria; insufficient evidence for all sleep disorders; moderate-to-high bias risk in most studies; promising leads for 6 specific conditions.

How the study worked

Systematic review searching PubMed, Scopus, Web of Science, Embase, CINAHL, and PsycInfo for preclinical and clinical studies of cannabinoid therapies for sleep disorders.

What this study cannot tell us

Limited number of studies meeting criteria; heterogeneous cannabinoid types, doses, and study designs; most studies had moderate-to-high bias risk; cannot draw condition-specific conclusions from few studies per disorder.

How to read the evidence

Moderate: comprehensive systematic review, but underlying evidence is sparse and mostly biased.

When this study was published

Published 2020.

The bigger picture

The disconnect between widespread cannabis-for-sleep use and minimal clinical evidence mirrors the CBD market broadly. Millions use cannabinoids for sleep based on anecdotal reports while rigorous trials remain scarce.

Questions still open

Which cannabinoid (THC, CBD, or combination) is most effective for each sleep disorder? Do cannabinoids improve objective sleep metrics or just subjective perception?

Common questions

Does cannabis help with sleep?

The evidence is surprisingly thin. This systematic review of 26 studies found insufficient evidence to recommend cannabinoids for any sleep disorder. However, promising preliminary findings exist for sleep apnea, insomnia, PTSD nightmares, restless legs syndrome, REM sleep behavior disorder, and narcolepsy.

Should I use CBD for insomnia?

Not based on current evidence. While many people report subjective sleep improvement, the clinical evidence does not yet support routine use. The authors call for larger, better-designed trials before recommendations can be made.

Read the original research

Cannabinoid therapies in the management of sleep disorders: A systematic review of preclinical and clinical studies.

Sleep medicine reviews, 53, 101339

View on PubMed ↗Publisher’s paper ↗

Citation

Suraev, Anastasia S; Marshall, Nathaniel S; Vandrey, Ryan; McCartney, Danielle; Benson, Melissa J; McGregor, Iain S; Grunstein, Ronald R; Hoyos, Camilla M. (2020). Cannabinoid therapies in the management of sleep disorders: A systematic review of preclinical and clinical studies.. Sleep medicine reviews, 53, 101339. https://doi.org/10.1016/j.smrv.2020.101339