Recreational drugs triple the risk of stroke in young people, study finds

Recreational drugs including cannabis, cocaine and amphetamines could significantly increase the risk of stroke in young people, a study suggests.

Stroke is the third leading cause of death and disability combined, and affects around 100,000 people every year in the UK. But making lifestyle changes such as eating healthy food, exercising and quitting smoking are known to cut the risk of stroke.

Researchers at the University of Cambridge also believe using recreational drugs, particularly amphetamines, could triple the risk of stroke in people under the age of 55, after analysing data from more than 100 million people.

Drugs could trigger a stroke by causing sudden spikes in blood pressure, heart rhythm problems and increased blood clotting, study authors suggest.

Dr Eric Harshfield, from the Department of Clinical Neurosciences at the University of Cambridge, said: “Our analysis suggests that it is these drugs themselves that increase the risk of stroke, not just other lifestyle factors among users. Taken together, our findings emphasise the importance of public health measures to reduce substance abuse as a way of helping also reduce stroke risk.”

About 8.7 per cent of people aged 16 to 59 years (approximately 2.9 million people) and 15.1 per cent of people aged 16 to 24 years (around 899,000 people) said they used “any drug” in the past 12 months, according to Office for National Statistics (ONS) data published in 2025.

There is already evidence to suggest recreational drugs may increase the risk of stroke, but most of the evidence is from observational studies, meaning it is impossible to say whether the use of these drugs itself increases the risk of stroke, or whether this is purely a correlation.

For the study published in the journal International Journal of Stroke, researchers carried out a meta-analysis of studies involving about 100 million people.

Cocaine and amphetamines were found to double the risk of stroke – cocaine increased the risk by 96 per cent and amphetamines by 122 per cent – while cannabis use increased the risk by 37 per cent.

But researchers found no significant link between opioid use and stroke risk.

Researchers then analysed the data for people under the age of 55 and found amphetamine use almost tripled the risk of stroke (an increase of 174 per cent), cocaine use increased the risk by 97 per cent, and cannabis use increased stroke risk by 14 per cent.

Analysis also revealed disordered cocaine use was associated with brain haemorrhage and cardioembolic stroke, which is caused by blood clots. Cannabis use disorders were associated with stroke overall, particularly large artery stroke.

A stroke happens when the blood supply to part of the brain is cut off, which kills brain cells and can affect how the body works, according to the Stroke Association.

Smoking, for example, is known to triple the risk of stroke by damaging blood vessels and increasing blood pressure.

Study authors suggest cannabis, cocaine and amphetamines increase the risk of spikes in blood pressure, blood vessel spasm and constriction, heart rhythm problems, increased blood clotting (especially cannabis), and inflammation or vasculitis (especially amphetamines).

Dr Megan Ritson, from the stroke research group at the University of Cambridge, said: “This is the most comprehensive analysis ever conducted on recreational drug use and stroke risk and provides compelling evidence that drugs like cocaine, amphetamines, and cannabis are causal risk factors for stroke. These findings give us stronger evidence to guide future research and public health strategies.”