People over 65 are being hospitalized 2700% more for this common pastime — which also increases dementia risk

Puff, puff, pass the medical bill. 

New research shows that emergency room visits and hospitalizations tied to cannabis use among older adults have increased nearly 27-fold since the aughts.

Even more alarming: The study found that seniors who end up in acute care for weed-related issues are up to 72% more likely to develop dementia than their peers who visited the hospital for other reasons or not at all.

Golden years go green

Although marijuana remains illegal at the federal level, 39 states and DC have legalized it for medical use, while 24 states — plus the capital — allow adults 21 and older to light up recreationally. 

As the green wave sweeps the nation, middle-aged and older adults have gotten in on the cannabis craze. A 2024 study found that 21% of people 50 and up have used marijuana in the past year, and 12% say they partake at least monthly. 

For these adults, cannabis serves a variety of purposes, including as a sleep aid, pain reliever, mental health support and simply to relax and feel good, according to University of Michigan researchers. 

Adults blaze their way to the ER

But lighting up can blunt your brain health.

“Long-term and heavy cannabis use has been associated with memory problems in midlife along with changes in brain structure associated with dementia,” said Dr. Daniel Myran, co-author of the study and a researcher at the University of Ottawa.

“We set out to estimate the risk of being diagnosed with dementia in a group of people whose cannabis use resulted in a visit to the emergency room or required hospitalization for treatment.”  

Myran and his colleagues analyzed the medical records of 6 million adults aged 45 and older in Ontario, Canada, who had no history of dementia when the study began.

Among them, 16,275 people with a history of cannabis use required acute care — either an ER visit or hospitalization — between 2008 and 2021.

Notably, the team found that the annual rate of adults over 45 seeking first-time acute care for cannabis use skyrocketed more than fivefold over the study period, increasing from 6.9 per 100,000 in 2008 to 37.6 per 100,000 in 2021.

The surge was even more dramatic among those 65 and older, with their rate jumping from 0.65 per 100,000 in 2008 to 16.99 per 100,000 by 2021, or a 26.7-fold increase.

High stakes

The study also raised concerns about a potential link between cannabis use and dementia. 

Researchers discovered that 5% of adults aged 45 and older who sought treatment for cannabis-related issues in acute care were diagnosed with dementia within five years.

In stark contrast, only 1.3% of the general population and 3.6% of those seeking care for other reasons developed dementia over the same period.

After adjusting for factors like age, sex, income and other health conditions, the study found that cannabis users were at a 23% greater risk of being diagnosed with dementia within five years compared to those who sought treatment for other reasons.

Even more alarming, cannabis users were found to be 72% more likely to develop dementia compared to the general population.

But there’s a twist: the study also revealed that the risk of dementia in individuals with acute care for cannabis use was 31% lower over the next five years compared to those who sought treatment for alcohol-related issues.

Investigating pot-ential causes

Researchers are still working to understand how cannabis impacts the brain.

“Regular cannabis use might directly increase the risk of dementia through changes in brain structure,” said Dr. Colleen Webber, co-author of the study and a scientist at the Bruyère Health Research Institute.  

“It’s also possible that regular cannabis use increases the risk of other established risk factors for dementia, including high blood pressure, head trauma and other injuries, and a higher risk for depression and social isolation,” she added. 

While the study findings are alarming, the authors noted two key limitations.

First, while they identified a potential link between heavy cannabis and acute care visits, they did not examine the effects of casual cannabis use that didn’t require emergency treatment.

Second, the study doesn’t prove that regular or heavy cannabis use causes dementia. Instead, researchers said the findings raise questions that need further exploration.