A major study has shown that cannabis addicts who have survived a stoke are almost 50 percent more likely to experience another.    

According to US doctors, people between the ages of 18 and 45 who smoke cannabis were 48% more likely than those without it to have another stroke.

Someone with a cannabis addiction disorder has an inability to stop using the drug. 

Although the jury is still not out, it remains to be determined if strokes can directly be caused by cannabis or if users are more likely to develop other risks factors. 

Some scientists claim the compounds in marijuana can cause inflammation – raising the chances of the stroke – or tighten blood vessels in the brain directly.  

The latest study, by researchers from Texas A&M University, claims to be the first time science has looked at the drug’s relationship with recurrent strokes.  

The health records of more than 160,000 young stroke survivors were examined by doctors in the US over two years. 

A recurrent stroke is a stroke that occurs when a stroke victim suffers another one in the weeks or months following their initial stroke. The risk of having another stroke decreases over time. 

Even though marijuana is legalized in some parts of the US, researchers warned about the dangers. The UK is slowly decriminalizing cannabis.  

Cannabis addicts were found to have a 48 per cent higher risk of being sent to hospital due to a repeated stroke in a new study of 160,000 young stroke survivors (stock image)

In a study of 160,000 stroke survivors, cannabis addicts had a 48% higher chance of having their strokes repeated. (stock photo)

A transient Ichaemic Attack (TIA), which temporarily interrupts blood flow to the brain, can lead to recurrent strokes. A TIA can be an indicator of a stroke. 

Researchers said that the researchers should do more to raise awareness about the risks associated with marijuana usage among youth.  

Previous research indicated that those who use cannabis are more likely to suffer from stroke, but doctors were interested in exploring the connection between repeated strokes and the drug. 

Cannabis is a popular drug in the UK as well as the USA. In 2019, there were approximately 2.6 million and 48.2million users in the respective countries.

In the new study doctors examined data from 161,390 Americans between the ages of 18 and 44 who were hospitalised between October 2015 and 2017 and who had previously suffered a stroke or TIA.

They found that 4,690 of these patients had been diagnosed as having a current addiction to cannabis.

Both the cannabis addict and non-addicted patients were average age 37.

The researchers found out that approximately 7 per cent of those addicted to cannabis had suffered a stroke in the past year, while the rate for people who did not have the addiction was only 5%. 

And after adjusting for patient factors such as age and other medical conditions, the researchers calculated that cannabis addicts were 48 per cent more likely to be hospitalised with recurrent strokes than their peers.     

Was the study able to reveal anything about cannabis addiction in young adults? 

The latest research examined data from 4,690 young people diagnosed with a cannabis use disorder and compared to it 156,700 people without.

It found that cannabis addiction was a major risk factor for strokes in people aged between 18 and 44. 

  • 55% of the affected men are males, as opposed to 40% who have it.
  • Being from a Black ethnicity is at 45%, as opposed to 37%.
  • It is also possible to smoke tobacco for 74%, versus 40%.
  • Chronic obstructive lung disease is a condition that causes breathing problems. It can be diagnosed at 21.5%, as opposed to 19.9%.
  • 20% are more likely to experience depression than 16%.
  • 11% are more likely to experience psychosis than 7.5%
  • One6.5 percent are more likely to drink than 4%. 

The researchers, who will present their findings at the American Stroke Association International Stroke Conference in New Orleans in the US on February 8, said the increased risk could be due to the variety of ways cannabis interacts with both blood supply and brain function.

The possible causes were the impairment in blood vessel function and increased risk of bleeding.     

Lead author of the study Dr Akhil Jain, an expert in biomedical engineering Texas A&M University, said the data showed a need to increase awareness of the risk of recurrent stokes from habitual cannabis among young people. 

He said, “It’s essential to increase awareness among young adults about the adverse effects of chronic, regular use of marijuana,” especially for those who have had stroke episodes or are at risk of developing cardiovascular disease. 

The authors acknowledge that there was a limitation to their research. They didn’t consider whether the drug used or the length of time they were using cannabis.

Dr Jain indicated that this area would be an important one for future research.

Strokes are caused by an interruption of blood supply to the brain, mostly due to a clot, called an ischaemic stroke, which accounts for 85 per cent of all cases.

Other cases are mostly due to a the bursting of a blood vessel which feeds the brain, called a haemorrhagic stroke. 

According to the UK’s National Institute for Health and Care Excellence, 26% of stroke victims will have another stroke within 5 years. This number rises to 39% a decade later. 

British charity The Stroke Association estimates the health and care costs of treating strokes in the UK is £4.38billion per year.

The UK Government’s  Drugs Misuse report for 2018-19 data showed that 2.6 million people in England and Wales used cannabis in that year, about 7.6 per cent of the adult population.

But, the rate of cannabis consumption rose to 17.3 Percent among young adults between 16 and 24, or 1.1million people. 

The US has 48.2million people. About 18% of them used cannabis at the least once.

In the latest study, data was also collected on general demographics and health information about US youth suffering from addiction to cannabis. 

The study found that the most common cannabis users were males, blacks, or both, as well as those with low income backgrounds. 

Their healthier counterparts were less likely to develop chronic obstructive airway disease (COPD) and other mental conditions, such as psychosis. 

The conference did not provide a complete copy of Dr Jain’s research and has yet to be peer reviewed. 


There are two main types of strokes: 


A stroke known as an ischemic stroke, which is responsible for 80 percent of all strokes, occurs when blood vessels blockages prevent blood from getting to a part of the brain.


The more rare, a hemorrhagic stroke, occurs when a blood vessel bursts, flooding part of the brain with too much blood while depriving other areas of adequate blood supply.

You could have an AVM or arteriovenous Malformation, which is an abnormal clustering of blood vessels in your brain.

Three quarters of those suffering from subarachnoid hemorhage die before reaching hospital. Another 25% die in less than 24 hours. Forty percent of survivors are also killed within one week.


A stroke is a condition that can be caused by high blood pressure, smoking and obesity.


  • Sudden weakness, numbness, or paralysis of the arms, legs, or face (especially on one side)
  • Sudden confusion or difficulty understanding, speaking or listening
  • Sudden blurred or blurred sight in either one or both eyes
  • Sudden dizziness, difficulty walking or coordination problems, and sudden loss of balance, dizziness, or loss in coordination
  • Sudden severe headache without any known cause


Many people will suffer lifelong disabilities after a stroke.

These include difficulty with walking, talking, eating and performing daily tasks. 


These are both potentially fatal and require immediate surgery or the use of a drug called TPA (tissueplasminogen activator).