Rationale: There has been a 70% rise in the risk of having a stroke for all ages in the last 30 years. A large portion of the increase is thought to be the result of preventable risk factors. (Felgin, 2025) Researchers wanted to know if Substance Use Disorders, including Cannabis Use Disorder (CUD), were contributing to this increase.

Method: Cambridge researchers conducted a meta-analysis on existing research that examines the relationship between Cannabis Use Disorder and stroke risk. Researchers reinforced their findings with a Mendelian Randomization study to eliminate hidden “third factors” and establish a cause-and-effect relationship.

Results: Cannabis use increased the risk of any stroke by 16%, and more than twice that risk (39%) for strokes due to blocked blood flow to the brain. Statistical techniques (Mendelian Randomization) were used to ensure no hidden “third factors” were contributing to the strokes.

The MR analysis showed that genes linked to CUD have an 11% increased risk for strokes in general, and a 35% increased risk for large artery strokes. Recent cannabis use did not correlate with stroke risk, which means that the risks are probably due to long-term exposure.

Meaning: Seldom use of Cannabis likely won’t kill you, but it can lead to an increase in your risk of any stroke – which definitely can – by over 10% and 35% for strokes that block blood flow to the brain. Even if you are young, the possibility of having a stroke will increase regardless of lifestyle or traits.