A growing number of Americans turn to marijuana to get a good night of rest, but a series of major scientific reports published in October 2026 indicates the habit may actually harm sleep quality and worsen breathing disruptions.
Among the most significant findings is an analysis from the long-running Coronary Artery Risk Development in Young Adults study, known as CARDIA. Published in JAMA Network Open, the investigation tracked participants over 35 years through examinations completed between 2020 and 2022. Researchers examined both cumulative cannabis exposure and recent consumption against objective measurements taken from wrist devices worn for seven days, the European Medical Journal reported.
The results showed that cumulative cannabis exposure, calculated in “cannabis-years,” was tied to worse sleep efficiency, greater fragmentation, and longer spells of wakefulness after falling asleep. Recent users were also more likely to spend longer periods awake at night compared to people who had never used the drug.
A gap between feeling and reality
Despite clear signs of disrupted rest recorded by monitors, study participants did not report lower sleep quality on subjective questionnaires like the Pittsburgh Sleep Quality Index. That discrepancy suggests consumers frequently believe cannabis aids their rest even when their bodies experience fragmented, less restorative sleep, according to findings cited by Psychology Today.
The lack of proven clinical benefit was also highlighted in a comprehensive Cochrane systematic review published on Oct. 13. Led by Dr. Lucia B. Varela of Universidad Hospital Italiano de Buenos Aires, researchers evaluated nine randomized controlled trials involving 537 adults diagnosed with insomnia, Ophthalmology Advisor reported. The review concluded that medical cannabis offered little to no clinically meaningful improvement in sleep quality, total sleep duration, or daytime functioning compared to placebos, while slightly increasing reported adverse side effects.
“The main message is that the research currently available is not sufficient to reliably answer whether medical cannabis helps people with insomnia,” Varela said in a statement.
Higher risks of nighttime breathing issues
Beyond fragmented rest, regular use may also interfere with airway stability. A separate study published in the journal Sleep Health examined data from 14,485 adults surveyed through the Centers for Disease Control and Prevention’s Behavioral Risk Factor Surveillance System in Minnesota and Tennessee, PsyPost reported.
Researchers discovered that frequent cannabis consumers faced significantly higher odds of sleep-disordered breathing symptoms, including loud snoring and observed pauses in respiration. After adjusting for variables such as body mass index, tobacco smoking, and alcohol consumption, adults who consumed cannabis 16 to 30 days per month experienced 73 percent higher odds of witnessed breathing cessations and 68 percent higher odds of loud snoring compared to non-users.
- Inhaling unfiltered, hot smoke can cause direct tissue inflammation and thermal irritation in the upper airway.
- Higher doses of cannabis may activate the parasympathetic nervous system, leading to excessive muscle relaxation in the throat that prompts airway collapse during sleep.
Lead author Dr. Tyler J. Gallagher, a resident physician at the Keck School of Medicine of the University of Southern California, told PsyPost that while infrequent consumption carries small risks, “the odds of irregular breathing during sleep almost double with more frequent cannabis use.”
Health authorities, including the American Academy of Sleep Medicine, currently advise against using cannabis to treat sleep apnea. Neither cannabis nor cannabidiol has received approval from the U.S. Food and Drug Administration to treat chronic insomnia, where cognitive behavioral therapy remains the recommended first-line approach. Researchers emphasize that larger, controlled clinical trials are still required to definitively determine whether cannabis directly causes airway problems or if struggling sleepers simply turn to the substance to self-medicate.
