There’s No Associated Between Cannabis Use and Increased Stroke Risk, Finds Study

Recent exposure to marijuana is not associated with an increased risk of ischemic stroke. This is according to a new study published in the journal Neurology: Clinical Practice. The study is titled Association between recent cannabinoid use and acute ischemic stroke.

For the study researchers with the University of Mississippi, Department of Neurology examined whether or not those testing positive for marijuana during a hospital admission screen were more likely to suffer from an acute ischemic stroke as compared to those who tested negative. According to NORML, who first reported on the study, researchers identified no link between recent cannabis exposure and either an increased or decreased risk of stroke after adjusting for confounders such as age, high blood pressure, and high cholesterol.

Marijuana Studies

They concluded: “Studies that have analyzed the association between cannabis use and acute ischemic stroke have provided conflicting results. … This is one of the few studies analyzing the association of recent cannabis use and acute ischemic stroke using admission urine toxicology test independent of polysubstance use. Even though our study has limitations, we did not find an independent association between recent cannabis use and the incidence of acute ischemic stroke. Further studies utilizing urine toxicology tests with larger sample size and including dosage of cannabis exposure should be done.”

According to NORML “The findings are inconsistent with those of a 2019 study published in the International Journal of Stroke which reported a higher risk of younger-onset stroke-related hospitalization among those who with a history of cannabis use. NORML has long cautioned that those with a history of cardiovascular disease may be at greater potential risk for adverse events from cannabis exposure.”



The full abstract of the study can be found below:

Objective: Studies that have analyzed the association between cannabis use and acute ischemic stroke have provided conflicting results. In this study, we aim to determine the association of recent cannabis use detected through urine drug screen among patients admitted with acute ischemic stroke.

Methods: A retrospective observational study was performed utilizing the medical records database. All patients 18 years and older admitted from January 1, 2015 to December 31, 2017 who underwent urine toxicology testing on admission were included in the analysis. Multivariate logistic regression analysis was done to analyze independent association between recent cannabis use and acute ischemic stroke.



Results: A total of 9,350 patients were determined to have undergone urine drug screen during admission and 18% (1,643) of this had a positive urine cannabis test. Unadjusted risk ratio showed a 50% decrease in risk of acute ischemic stroke among cannabis users (RR = 0.505, 95% CI 0.425 – 0.600). The effect was lost after adjusting for age, race, ethnicity, sickle cell disease, dyslipidemia, hypertension, obesity, diabetes mellitus, cigarette smoking, atrial fibrillation, and other cardiac conditions (OR 1.038, 95% CI 0.773-1.394).

Conclusion: This is one of the few studies analyzing the association of recent cannabis use and acute ischemic stroke using admission urine toxicology test independent of polysubstance use. Even though our study has limitations, we did not find an independent association between recent cannabis use and the incidence of acute ischemic stroke. Further studies utilizing urine toxicology tests with larger sample size and including dosage of cannabis exposure should be done.

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