Study finds cannabis use raises stroke risk by 37% in large-scale analysis

A team from the University of Cambridge's Department of Clinical Neurosciences performed a meta-analysis covering studies with over 100 million individuals to assess the link between illicit drug use and stroke. Their findings, published in the International Journal of Stroke, show that cocaine and amphetamines each roughly double the overall stroke risk (96% and 122% increases respectively), while cannabis use corresponds to a 37% rise.

Among adults younger than 55, amphetamines increase risk by 174%, cannabis by 14%, and cocaine by 97%. Mendelian randomisation analyses indicated that cocaine use disorders are strongly tied to brain hemorrhage and cardioembolic stroke, and cannabis use disorders to overall and large-artery stroke, supporting a possible causal link. The study also noted that problematic alcohol use elevates certain stroke subtypes.

Researchers attribute the heightened risk to mechanisms such as blood-pressure spikes, vessel constriction, arrhythmias, clotting, and inflammation. Funding came from the British Heart Foundation and the NIHR Cambridge Biomedical Research Center.