Cannabis, cocaine and amphetamines all raise the risk of stroke significantly. That is the central finding of the largest study ever conducted on recreational drugs and stroke risk, drawing on data from more than 100 million people. Researchers at the University of Cambridge published their findings in the International Journal of Stroke in March 2026. The study concludes that these substances do not merely correlate with stroke. They appear to cause it.
The Statistics on Drug Use and Stroke Risk
The study found cocaine use raises stroke risk by 96%. Amphetamines raise it by 122%. Cannabis, often seen as the softer option, still increases the risk by 37%. Researchers found no significant link between opioid use and stroke.
Among adults under 55, the numbers become even more striking. Amphetamine use raises stroke risk by 174% in this age group. That is nearly three times the average person’s risk. Cocaine use in younger adults still carries a 97% elevated risk. Cannabis raises it by 14% in the same group.
Stroke is the third leading cause of death and disability combined worldwide. Most people associate it with older age, high blood pressure or poor diet. This research now adds drug use and stroke to that list of major, modifiable risk factors.
In England and Wales, around 2.9 million adults aged 16 to 59 reported using a recreational drug in 2024. That represents 8.8% of that age group. In the United States, more than half of all people over the age of 12 report having used cocaine, cannabis or opiates at least once.
Recreational Drugs and Stroke Risk: Moving Beyond Correlation
Earlier studies could show a connection between drug use and stroke. But they could not confirm the drugs were the actual cause. Other lifestyle factors among users clouded the picture.
The Cambridge team used a method called Mendelian randomisation to dig deeper. This technique looks at naturally occurring genetic variants linked to drug use and to stroke. It tests whether a true causal relationship exists between the two. The results pointed clearly toward cause, not just correlation.
Cocaine use disorders showed a strong connection to brain haemorrhage and cardioembolic stroke. In cardioembolic stroke, a blood clot forms in the heart and travels to the brain, cutting off blood flow. Cannabis use disorders linked most strongly to large artery stroke.
Dr Megan Ritson from the Stroke Research Group at the University of Cambridge said the research “provides compelling evidence that drugs like cocaine, amphetamines, and cannabis are causal risk factors for stroke.”
Dr Eric Harshfield, an Alzheimer’s Society Research Fellow at the Department of Clinical Neurosciences, was equally direct. He stated that the analysis shows it is the drugs themselves driving the elevated risk, not simply the broader lifestyle of those who use them.
How Recreational Drugs Damage the Brain
The body reacts to these substances in several ways that are known to trigger stroke. Blood pressure spikes sharply and suddenly. Blood vessels go into spasm and constrict. Heart rhythm becomes disrupted. Cannabis use promotes increased blood clotting. Amphetamines can cause inflammation of blood vessel walls.
Each of these reactions is a recognised pathway to stroke. They can lead to ischaemic strokes, which blood clots cause, and to haemorrhagic strokes, which involve bleeding in the brain. The danger does not require years of heavy use. These effects can strike acutely, even in otherwise healthy adults.
What the Research Means for Public Health
Drug use and stroke share a relationship that public health policy can no longer ignore. Dr Harshfield emphasised that reducing substance use would carry a meaningful benefit beyond addiction itself: a measurable reduction in stroke cases.
The research received funding from the British Heart Foundation, with additional support from the National Institute for Health and Care Research Cambridge Biomedical Research Centre.
The evidence now speaks plainly. For more than 100 million reasons, recreational drugs and stroke risk belong in the same sentence.
Source: WRD-News
