A new study from the University of Cambridge analyzing data from over 100 million people reveals that cannabis, cocaine, and amphetamines can more than double the risk of stroke, even in younger individuals. Understanding these lesser-known risk factors is crucial for public health.
Drug use can significantly harm the brain, and new research indicates a link to increased stroke risk, particularly among younger people. According to the study, using amphetamines more than doubles the probability of stroke, and nearly triples it in those under 55.
Amphetamines, Cocaine, and Cannabis
The findings arrive from research at the University of Cambridge, which re-analyzed data from over 100 million people across more than 30 studies to assess the impact of drug use on the likelihood of cerebral stroke. The analysis showed that amphetamine use increases stroke risk by 122 percent, rising to 174 percent for individuals under 55. Cocaine, already known to increase the risk of heart attack, is associated with a roughly 96 percent increase in stroke risk across all age groups. Researchers also found that cannabis use is linked to a 37 percent higher probability of stroke.
The authors emphasize that the connection appears to be causal, not merely correlational. Further analysis using Mendelian randomization—a method employing genetic variations to understand cause-and-effect relationships—demonstrated that cannabis use is associated with ischemic strokes in larger blood vessels, cocaine with hemorrhagic and cardioembolic strokes.
Cause and Effect
These specific associations suggest a causal relationship, which researchers explain by noting that these drugs can cause spikes in blood pressure, artery spasms, irregular heartbeats, increased atherosclerosis (particularly with cocaine), increased blood clotting (especially with cannabis), and inflammation of blood vessels (especially with amphetamines). “Our analysis suggests that these drugs of abuse increase the risk of stroke independently of other risk factors,” the researchers stated. Juliet Bouverie, of the British Stroke Association, highlighted that “these substances put stress on the cardiovascular system, promoting the formation of blood clots, narrowing of blood vessels, and cardiovascular damage. Regular cocaine use, for example, can lead to hypertension, which causes about half of all strokes.”
Warning Signs
Stroke is an acute event, but it develops gradually over time, according to the Italian Association for the Fight Against Stroke (A.L.I.Ce. Italia Odv). The association notes that there are early, often overlooked, warning signs that could support identify individuals at risk. Stress is one such factor, as it increases blood pressure, stiffens blood vessels, and promotes low-grade inflammation—all of which contribute to clot formation, and stroke. “Chronic stress is not just an emotional or psychological problem; it’s a persistent biological stimulus that profoundly alters cardiovascular balance over time, favoring stroke,” explained Valeria Caso, head of the Neurology – Stroke Unit at the Saronno Hospital.
Pay Attention to Sleep
Evaluating sleep patterns can also help assess stroke risk. Sleep is a fundamental phase of regulation and recovery, and should be sufficient in both quantity and quality. Sleeping less than five or six hours a night, or more than eight or nine, increases stroke risk; those with disturbed sleep due to obstructive sleep apnea have approximately double the risk. Long, involuntary naps during the day should also raise concern: one study indicates that short naps, up to 30 minutes, have no impact, but naps exceeding 1.5 hours increase risk by 80 percent, and involuntary naps carry an even greater risk. “Frequent and involuntary daytime sleepiness can be a sign of non-restorative nighttime sleep or disorders such as obstructive sleep apnea, which we know increases stroke risk,” said Massimo Del Sette, director of the Neurology Unit at the San Martino Polyclinic in Genoa. “The increased risk was observed for all major types of stroke: ischemic, hemorrhagic, and subarachnoid.” The association urges individuals not to underestimate frequent, prolonged, or involuntary naps, especially if recent or increasing, and to discuss them with a doctor to evaluate cardiovascular risk and sleep disorders. Because the brain often sends signals long before a stroke manifests.
