Recreational cannabis use and sleep in the general population: a systematic review and meta-analysis.

Cannabis use is often used to improve sleep, yet it remains unclear whether its recreational use, either current or lifetime, is associated with better sleep in the general population. We conducted a systematic review and meta-analysis of 120 studies identified from six databases, excluding studies on medicinal cannabis or clinical samples. Current use was defined as cannabis use within one month, and lifetime use as use in the past year or lifetime. Among 102 observational studies identified, current recreational cannabis use was associated with poorer sleep quality, both short and long sleep duration, more insomnia symptoms, and a later chronotype, compared to non-use. Lifetime use showed similar associations with insomnia and chronotype. Neither current nor lifetime use was linked to daytime sleepiness. These associations were more pronounced among men and younger users. In contrast, no associations between cannabis and sleep quality and duration were observed across 19 experimental studies. Overall, recreational cannabis use was linked to poorer sleep across multiple components in observational studies although these findings may be affected by bias. Given the ethical and practical limitations of long-term trials, integrating well-designed observational and experimental research is essential to fully understand how cannabis use links to sleep.