A new study from Northwestern Medicine indicates that cannabis, commonly used by millions of Americans as a sleep aid, may not actually improve sleep quality as many believe. The research, published on October 9 in JAMA Network Open, found that both lifetime and recent cannabis use were associated with poorer sleep quality, contrary to participants' own perceptions.
Read More
The study followed participants from young adulthood into middle age over nearly 35 years, monitoring their cannabis use over time. In middle age, participants wore wrist-based sleep monitors for a week and completed surveys about their sleep. Results showed that despite the use of cannabis, many participants did not report sleeping worse than non-users.
Dr. Thanh-Huyen T. Vu, the study's corresponding author and a research associate professor at Northwestern University Feinberg School of Medicine, emphasized that the findings challenge the belief that cannabis enhances sleep, suggesting that it may actually correlate with lower sleep quality. Senior author Mercedes R. Carnethon, chair of the department of preventive medicine at Feinberg, reinforced this point, noting that the study provides substantial evidence that long-term recreational cannabis use may not coincide with good sleep quality.
The research drew data from the Coronary Artery Risk Development in Young Adults (CARDIA) Study, which began in 1985-86 and tracks Black and white adults in the U.S. Among the 1,266 participants, those with greater lifetime cannabis exposure experienced more sleep disturbances, spent less time asleep, and demonstrated more fragmented sleep patterns.
Recent cannabis users also exhibited similar issues, including lower sleep efficiency and increased nighttime wakefulness. Interestingly, when asked to evaluate their own sleep, cannabis use did not correlate with participants’ assessments of sleep quality.
The study adjusted for various influencing factors including age, race, and other substance use, yet cannabis use was still linked to objectively measured poorer sleep. The authors also noted that they did not differentiate between methods of cannabis consumption, an important detail for future research.
Co-author Kristen L. Knutson, associate professor of neurology at Feinberg, suggested alternative ways to enhance sleep quality, such as establishing a regular bedtime, creating a conducive sleep environment, and avoiding screen time before bed. For persistent sleep problems, she advised consulting a healthcare provider.
The study, titled "Recent and Cumulative Cannabis Use and Sleep in Middle-Aged Adults," was supported by several grants from the National Heart, Lung, and Blood Institute and associated institutions.