Are Sweet Dreams Made of These? Understanding the Relationship Between Sleep and Cannabis Use

There is widespread literature on the interaction between cannabis use and sleep, yet the mechanisms that underlie this relationship are not well understood. Several factors lead to inconsistencies in this relationship suggesting a nuanced interaction between cannabis and sleep. An important question that remains to be addressed is the temporal relationship between disrupted sleep and cannabis use. This literature review summarizes the existing literature on the association between disrupted sleep and cannabis toward the goal of addressing the question of the chronology of these reported effects. We conducted a review of the literature using PubMed to summarize current knowledge on the association between cannabis use and sleep in humans. We identified 31 studies on the association of cannabis use and sleep. The findings from these studies were mixed. Cannabis was associated with a variety of impacts on sleep ranging from beneficial effects, such as reduced sleep-onset latency, to negative outcomes, such as reduced sleep duration and suppressed rapid eye movement oscillations. The chronology of the interaction of cannabis and sleep was unclear, although much of the current literature focus on factors that modulate how cannabis impairs sleep after initial use. There was sufficient evidence to suggest that cannabis use alters circadian rhythms, and hence, negatively impacts sleep. The current literature is largely from studies utilizing self-report measures of sleep; thus, objective measures of sleep are needed. In addition, although there were no empirical studies on the temporal relationship between cannabis use and sleep, the majority of the literature focused on characterizing sleep impairment after cannabis use.