The effects of cannabis on sleep, circadian rhythms, and cognition in young adults

Cannabis legalization is increasing steadily in the United States, coinciding with an increase in recreational use and THC potency. Chronic cannabis use is associated with altered sleep structure and mild cognitive deficits in learning and memory compared to non-users. Researchers have found evidence that chronic administration of THC disrupts circadian signaling on the molecular level (Lafaye et al., 2019), while others propose that chronic cannabis use may act as a signaling cue for rhythmicity (Whitehurst et al., 2015). This conceptual replication of Whitehurst’s study investigates the effects of chronic cannabis use on sleep, circadian rhythm, and cognitive performance of young adults by comparing chronic users’ sleep parameters, circadian rhythm patterns, and cognitive performance to non-cannabis using age-matched controls. Participants were given an actigraph device to monitor sleep and activity for two weeks, morning and evening sleep/substance use journals, sleep questionnaires, and the Automated Neuropsychological Assessment Metric (ANAM). Urinalyses were conducted to confirm group membership. No significant differences were identified between groups in sleep patterns, circadian rhythm, and cognitive performance. Within the chronic cannabis user group, frequency of reported use and years of chronic use displayed predictive properties for select cognitive domains and sleep parameters.