For many young adultsa joint with friends or a line in the evening seem far from the serious image of a stroke. However, a large study from the University of Cambridge shakes up this impression of security and suddenly brings together festive evenings and neurology departments.
By analyzing data from more than 100 million people, researchers examined the impact of major
recreational drugs on the risk ofStrokeincluding before age 55. Their results, published in the journal International Journal of Strokeshow that cannabis, cocaine and amphetamines are associated with a marked increase in strokes, a disease that is already the third leading cause of death and disability in the world. Among those under 55, certain risks are almost tripled.
Recreational drugs and stroke: an unprecedented study
The team from the Department of Clinical Neurosciences at the University of Cambridge carried out a meta-analysis of 32 studies, bringing together more than 100 million medical records. She compared people who used cannabis, cocaine, amphetamines or opioids to those who did not, then used a statistical approach, Mendelian randomization, to test whether the link resembled a true cause-and-effect relationship. No significant link was found for opioids.
For Dr Megan Ritson, from the Stroke Research Group at the University of Cambridge, who led this work, “This is the most comprehensive analysis ever conducted on recreational drug use and stroke risk. It provides compelling evidence that drugs such as cocaine, amphetamines and cannabis are risk factors for stroke. These findings provide us with stronger evidence to guide future research and public health strategies“.
Among those under 55, risks are exploding!
In the general population, the use of amphetamines is associated with a 122% increase in the risk of stroke, that of cocaine with a 96% increase, and that of cannabis with a 37% increase. The authors also note that problematic alcohol use increases certain types of stroke, while smoking is already known to triple the risk. Clearly, in the same individual, these factors can add up.
When the analyzes focus on those under 55, the figures become even more striking: the risk of stroke is increased by 174% with amphetamines, i.e. an almost tripled risk97% with cocaine and 14% with cannabis.
Cocaine-related disorders are mainly associated with hemorrhagic strokes (related to a rupture of a vessel, such as an artery, and causing bleeding inside the brain) and ischemic strokes (where a blood clot forms in the heart and travels to the brain, blocking blood flow and causing damage to brain tissue) while cannabis-related disorders are linked to strokes affecting large arteries. Problematic alcohol use was associated with increased risk of ischemic stroke and large vessel stroke, while alcohol dependence increased the risk of stroke overall.
A direct alert for young French people
In France, the “Drugs and Addictions” report estimates that there are 900,000 daily cannabis users, 1.1 million annual cocaine users and 750,000 ecstasy/MDMA users. In a context where the UN mentions around 300 million illicit drug users worldwide, these new figures are worrying: around nine out of ten strokes are preventable by acting on modifiable factors such as diet, physical activity, blood pressure… and drug consumption.
Researchers say potential reasons for the link between these substances and increased risk of stroke include sudden increases in blood pressure, spasms and narrowing of blood vessels, heart rhythm abnormalities, increased blood clotting (particularly with cannabis), and inflammation or vasculitis (particularly with amphetamines). These mechanisms are well known to cause ischemic strokes, caused by blood clots, as well as hemorrhagic strokes.
Dr Eric Harshfield, Alzheimer’s Society Researcher in the Department of Clinical Neurosciences, said:
“Our analysis suggests that it is these drugs themselves that increase the risk of stroke, not just other lifestyle factors of users. Taken together, our findings highlight the importance of public health measures aimed at reducing substance abuse to also help reduce stroke risk.“.
These are all pathways known to cause ischemic strokes, linked to a clot, or hemorrhagic strokes, linked to the rupture of a vessel. Finally, prevention organizations remind us that when faced with a face that is paralyzed on one side, an arm that no longer raises or sudden speech problems, even in a young person, you must call 15 without delay.