Meta-Analysis Finds Cannabis Users Have Twice the Risk of Ischemic Stroke

Pooled analysis of seven studies revealed a statistically significant association between cannabis use and ischemic stroke risk (pooled OR = 2.05, 95% CI: 1.46-2.87, p < 0.001). Moderate heterogeneity was present (I-squared = 68.9%, p = .007).

Systematic review and meta-analysis following PRISMA guidelines. Searched PubMed, Web of Science, Scopus, Embase, and Google Scholar through March 2025. Seven studies (2007-2023) including case-control, cohort, and cross-sectional designs met inclusion criteria. Random-effects model used for pooling. Quality assessed with JBI checklist.

Ischemic stroke among young adults is increasing globally, paralleling rising cannabis use. This meta-analysis provides the strongest pooled evidence to date that cannabis use approximately doubles stroke risk, a finding with particular relevance as legalization expands and cannabis is increasingly perceived as low-risk.

Cannabis can trigger vasospasm, affect cerebral blood flow, and promote prothrombotic states through various mechanisms. The doubling of stroke risk is particularly concerning for young adults, who may not be screened for stroke risk factors and who disproportionately use cannabis.

Only seven studies met inclusion criteria, reflecting the limited evidence base. Moderate heterogeneity suggests variability across studies. Most studies relied on self-reported cannabis use and could not control for dose, frequency, or method of consumption. Observational designs cannot prove causation.