Medical Cannabis Shows Little Benefit for Insomnia in Adults

TOPLINEMedical cannabis had little or no clinically meaningful effect on sleep quality, daytime functioning, or total sleep time in adults with insomnia, but the quality of evidence was uncertain, a meta-analysis showed. Medical cannabis was also linked to a slight increase in adverse events (AEs) compared with placebo.METHODOLOGYResearchers conducted a systematic review and meta-analysis of randomized controlled trials evaluating medical cannabis for insomnia in adults, searching databases through April 2025.A total of 537 adults aged 18-76 years who had insomnia (mean age, 44.79 years; 72.66% women) were included across nine studies.Eight studies compared medical cannabis with placebo, and one compared it with amitriptyline. Seven trials used pharmacy-compounded (magistral) preparations; the other two tested licensed products, one plant-based and the other synthetic.Participants predominantly had primary insomnia (eight studies), with one study focusing on insomnia associated with fibromyalgia; six studies assessed chronic insomnia, and three assessed acute insomnia.Outcomes included quality of sleep/satisfaction with sleep, total sleep time, AEs, sleep onset latency, wake after sleep onset, daytime functioning, and quality of life. Follow-up lasted up to 12 weeks.TAKEAWAYMedical cannabis had little or no clinically meaningful effect on total sleep time (mean difference [MD], 7.68 minutes; 95% CI, -23.04 to 38.39; n = 194 participants), quality of sleep/satisfaction with sleep (standardized MD [SMD], -0.49; 95% CI, -1.06 to 0.08; n = 374), or daytime functioning (SMD, -0.34; 95% CI, -0.83 to 0.16; n = 144) compared with placebo. The evidence had very low certainty.Medical cannabis use was linked to an increase in AEs (odds ratio [OR], 11.25; 95% CI, 4.46-28.35; n = 98; low-certainty evidence), with 37 participants experiencing AEs during the intervention period, none during the placebo period, 14 during both periods, and 47 during neither period.Medical cannabis use showed benefits for quality of life (SMD, 0.84; 95% CI, -0.61 to 2.29; n = 95), but the evidence was inconclusive.No clear effect was observed on sleep onset latency (MD, -4.30 minutes; 95% CI, -26.82 to 18.22) or wake after sleep onset (MD, -2.79 minutes; 95% CI, -34.40 to 28.82).IN PRACTICE"The main message is that the research currently available is not sufficient to reliably answer whether medical cannabis helps people with insomnia. This does not mean that medical cannabis is ineffective. It means that, based on the evidence we have, we cannot draw reliable conclusions about its effectiveness for insomnia in the general population," lead author Lucia Varela, University of Manitoba, Winnipeg, Canada, said in a press release.SOURCEThe study was published online on October 13 in the Cochrane Database of Systematic Reviews.LIMITATIONSMost included studies had a high risk of bias. The analysis was limited by small sample sizes, wide confidence intervals, and high statistical heterogeneity. The analysis relied on cross-over trials and lacked sex- and age-disaggregated data. Studies predominantly included middle-aged adults with primary insomnia, underrepresenting older adults and individuals with comorbidities, limiting the applicability of the findings.DISCLOSURESThe study did not receive any specific funding. The authors reported no relevant conflicts of interest.This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.