Researchers at the University of Cambridge conducted a meta-analysis of studies involving over 100 million participants, finding that cannabis, cocaine, and amphetamines are significantly associated with an increased risk of stroke. Specifically, cocaine and amphetamine use were linked to approximately double the risk of stroke (96% and 122% increases, respectively), while cannabis use was associated with a 37% higher risk. Opioid use, however, did not show a statistically significant association with stroke risk. The study, published in the International Journal of Stroke, also noted that among individuals under 55, amphetamine use was associated with a 174% increased risk, cannabis with a 14% increase, and cocaine with a 97% increase.
To explore potential causal relationships, the researchers employed Mendelian randomization, a method using genetic variants to assess whether drug use disorders causally contribute to stroke risk. The genetic analysis indicated that cocaine use disorders were particularly associated with brain hemorrhage and cardioembolic stroke, while cannabis use disorders were linked to stroke overall, especially large artery stroke. These findings suggest that the drugs themselves, rather than confounding lifestyle factors, may directly elevate stroke risk through mechanisms such as increased blood pressure, blood vessel spasms, abnormal heart rhythms, heightened blood clotting, and inflammation. The study underscores the importance of public health measures to reduce substance abuse as a strategy for mitigating stroke risk. [Source: https://www.sciencedaily.com/releases/2026/08/2608220152.htm]