Study Suggests Marijuana Use May Be Linked To Higher Dementia Risk Within Five Years

A recent study has linked cannabis use to an increased risk of dementia in certain cases, raising new concerns about long-term effects.

Yesterday marked 4/20 April 20—a date widely celebrated by marijuana users. People in over 20 U.S. states where recreational weed is legal likely lit up to mark the day.

With stars like Snoop Dogg, Seth Rogen, Miley Cyrus, Whoopi Goldberg, and Wiz Khalifa often endorsing it, cannabis has definitely gone mainstream in pop culture. But despite its popularity, experts continue to caution that frequent or heavy use can still come with some serious health risks.

One such health concern has come to light through a new study that appeared last Monday in the journal JAMA Neurology, which is hosted by the U.S. National Library of Medicine.

After examining the medical records of more than six million individuals, researchers found a connection between cannabis-related hospital visits and a higher likelihood of developing dementia later on.

"Someone who has an emergency room visit or hospitalization due to cannabis has a 23% increased risk of dementia within five years compared to someone who was at the hospital for another reason. They have a 72% greater risk compared to the general population." Dr. Daniel Myran, one of the study's Canadian co-authors, told CNN.

Dr. Myran, who works as an assistant professor in the Department of Family Medicine at the University of Ottawa, added: "Those numbers have already factored out other reasons for dementia, such as age, sex, mental health or substance use, and whether or not you have chronic conditions such as diabetes or heart disease."

Past research already suggested that people who use cannabis are about 25 percent more likely to need emergency care compared to those who don't use it.

He continued: "However, this is not a study that anyone should look at and say, 'Jury's in, and cannabis use causes dementia'. This is a study that brings up a concerning association that fits within a growing body of research."

The study’s abstract also noted: "Cannabis use is associated with short-term memory impairment and long-term changes in brain structure; however, little is known about whether disordered cannabis use is associated with an increased risk of a dementia diagnosis."

Among the six million individuals included in the analysis, roughly 16,000 or about 0.3 percent had been admitted to a hospital or ER because of cannabis-related issues. Most of these patients were around the age of 55, and about 60 percent of them were male.

Between 2008 and 2021, cannabis-related hospitalizations rose sharply. Among people aged 45 to 64, these visits increased fivefold. In adults aged 65 and older, the increase was even steeper nearly 27 times more frequent.

Results found that five percent of people with cannabis-related visits developed dementia Getty stock

The study found that people who had gone to the hospital due to cannabis use were significantly more likely to be diagnosed with dementia within five years. In fact, they were about 1.5 times more likely than people who went to the hospital for other reasons.

Of those with cannabis-related hospital visits, five percent were later diagnosed with dementia. That compares to 3.6 percent for those hospitalized for other reasons, and just 1.3 percent among the general population.

Even after researchers adjusted for factors like age, existing health conditions, and lifestyle habits, the dementia risk remained higher for the cannabis group. Still, it's worth noting that their risk was actually lower than individuals who had been hospitalized for alcohol-related reasons.