Heavy Cannabis Use Actually Hurts Sleep—and Memory: Study

Summary: A recent study led by researchers from The University of Texas at Dallas and the University of Amsterdam has revealed that long-term cannabis use negatively impacts both sleep and memory. The study, which included 141 adults with cannabis use disorder and 87 non-users, found that those with cannabis use disorder reported more sleep problems, which were linked to poorer visuospatial memory performance. Interestingly, no differences were observed between the two groups in terms of verbal memory. Researchers say the findings highlights the need for a deeper understanding of how cannabis affects sleep and memory, especially for consumers and policymakers considering its therapeutic use.

Key Takeaways:

Long-Term Cannabis Use Linked to Sleep Issues: Individuals with cannabis use disorder reported more frequent sleep problems than non-users, despite cannabis often being used as a sleep aid.
Poor Sleep Affects Memory in Cannabis Users: The study found a clear connection between sleep disturbances and visuospatial memory problems in regular users, highlighting a cognitive impact of sleep loss.
Verbal Memory Unaffected: Despite the sleep issues and visuospatial memory problems, no significant differences were found between cannabis users and non-users in terms of verbal memory performance.

The growing legal use of recreational and medical cannabis has generated an increased concern for potential side effects from long-term use, particularly regarding problems with memory and sleep.

Until now, the effects of cannabis use on sleep and on memory have only been studied separately. Research led by Francesca Filbey, PhD, from the Laboratory of Neuroimaging of Reward Dynamics at The University of Texas at Dallas’ Center for BrainHealth, in collaboration with a team from the University of Amsterdam, aimed to fill this gap by testing how sleep impacts memory among cannabis users.

The study was published in The American Journal of Drug and Alcohol Abuse.

Impact of Regular Cannabis Use

A total of 141 adults with cannabis use disorder (defined as using cannabis regularly, more than five days per week during the past year) and 87 non-current users participated in this study.

Participants self-reported their frequency of sleep problems within the past week and completed a variety of cognitive assessments that tested their verbal memory, visuospatial learning, and memory performance.

Results revealed that the cannabis use disorder group reported more sleep problems than the non-cannabis use disorder group and that this contributed to visuospatial memory problems as well. There was no difference between the two groups in verbal memory performance.

Implications

“Although sleep is one of the primary reasons people use cannabis, our findings suggest that long-term cannabis use actually results in poorer sleep, which is associated with poorer memory,” says lead author Tracy Brown, a UT Dallas psychology PhD student in Filbey’s lab, in a release. “These findings are useful to inform the consumers, clinicians, and policymakers about the therapeutic considerations for cannabis, particularly regarding its use as a sleep aid.”

He adds in a release, “For researchers, this study points to the importance of analyzing sleep when evaluating the effects of cannabis on brain health.”

This research was supported by a grant from the National Institute on Drug Abuse/National Institute of Health.