Amphetamines don’t just double your stroke risk if you’re young — they nearly triple it. That’s not a scare-tactic headline; it’s the finding of the largest study of its kind ever conducted, and it lands at a moment when recreational drug use among younger adults is treated, culturally, as low-stakes.
According to a release from the University of Cambridge and coverage by EurekAlert, researchers in the university’s Department of Clinical Neurosciences pooled data from 32 prior studies covering more than 100 million people to examine the relationship between recreational drug use and stroke risk. The findings were published in the International Journal of Stroke.
Across all participants, the study found that cocaine use was associated with a 96% higher risk of stroke and amphetamine use with a 122% higher risk — both roughly doubling the baseline risk, according to Cambridge’s release. Cannabis use was linked to a 37% increase. The researchers found no statistically significant association between opioid use and stroke risk, according to the Department of Clinical Neurosciences.
When the team narrowed its analysis to adults under 55, the effects grew sharper. U.S. News & World Report and health outlet WRD News reported that amphetamine use in this younger group was linked to a 174% increase in stroke risk, cocaine to a 97% increase, and cannabis to a 14% increase.
To test whether these were genuine causal relationships rather than coincidental associations, the researchers applied a technique called Mendelian randomization, which uses naturally occurring genetic variants linked to risk factors to evaluate causality, according to the Department of Clinical Neurosciences. Lead researcher Megan Ritson, a postdoctoral research associate at Cambridge, said in the university’s release that the analysis is the most comprehensive of its kind ever conducted and provides compelling evidence that cocaine, amphetamines, and cannabis are causal risk factors for stroke, not just markers of other risky behavior.
Psychology Today reported that drug use is already the most common predisposing condition behind strokes in people under 35, a group in which stroke has traditionally been considered rare. Outlet NanoApps Medical, citing the Cambridge team, noted the drugs appear to raise stroke risk through several physiological pathways, including sudden blood pressure spikes, blood vessel narrowing, irregular heart rhythms, increased blood clotting linked especially to cannabis, and vascular inflammation linked especially to amphetamines.
Cambridge’s release also noted that stroke remains the third leading cause of death and disability combined worldwide, and cited UK government data showing 8.8% of adults aged 16 to 59 in England and Wales reported using an illegal or legal recreational drug in the past year as of 2024 — around 2.9 million people.
The generational angle is the part likely to get buried under the topline stats, and it shouldn’t be. A near-tripling of stroke risk in people under 55 rewires a core assumption baked into how most people think about their own mortality — that stroke is a decades-away problem, not a this-decade problem. If public health messaging doesn’t catch up to what this data actually shows, particularly around stimulants like cocaine and amphetamines, the study risks becoming another well-cited paper that never reaches the people who most need to hear it.
If you or someone you know is affected by substance use and wants support, speaking with a doctor or a local addiction support service is a reasonable place to start.