A recent study suggests a potential link between cannabis use requiring medical attention and an increased risk of developing dementia later in life. Researchers at the Institute for Clinical Evaluative Sciences (ICES) analyzed data from over six million individuals aged 45 to 105 in Ontario, Canada, spanning from 2008 to 2021.
The findings, published in *JAMA Neurology*, revealed a concerning trend: those who sought emergency care for cannabis-related issues demonstrated a significantly higher likelihood of receiving a dementia diagnosis within five years. Specifically:
- Individuals with an emergency department visit related to cannabis use showed a 23% greater risk of dementia.
- Those requiring hospitalization due to cannabis use faced a considerably larger risk, at 72%.
The study observed a dramatic increase in acute care episodes linked to cannabis over the period studied. Annual rates rose fivefold between ages 45 and 64, and an astonishing 26.7 times for individuals over 65.
“Because of our study design, it is important to note that this doesn’t mean cannabis use causes dementia, but it highlights a concerning association,” explained Dr. Daniel Myran, lead author of the study and an ICES scientist.
The heightened risk remained apparent even after accounting for other potential influencing factors such as existing medical conditions, socioeconomic status, and prior treatment for substance abuse or mental health concerns.
Researchers noted a particularly surprising increase in cannabis-related emergency room visits and hospitalizations among older adults. “It increased by over five times, from 353 in 2008 to 2,508 in 2021,” stated Dr. Myran. “In adults aged 65 or older , it went up 27 times.”
The study also revealed that among those who sought emergency care and were later diagnosed with dementia, the prevalence was notably high: 5% within five years and 19% over a ten-year period.
While the research provides valuable insights, limitations exist. The study lacked detailed information regarding individual cannabis use patterns or other lifestyle factors like smoking, potentially contributing to some of the observed risk differences.
“We also only examined the risk of dementia for individuals whose cannabis use led to an emergency visit or hospitalization — this is a small and higher-risk subset of all cannabis users and doesn’t tell us about the potential risks of differing patterns of cannabis use,” Dr. Myran acknowledged.
Despite the increasing legalization of medical and recreational cannabis, experts caution that its use is not without potential harm. “Like alcohol and other substances, cannabis use – especially regular cannabis use or use of higher-strength products – may come with important risks,” warned Dr. Myran.
He concluded, “Our findings add to a growing body of research suggesting that regular cannabis use may have negative impacts on brain health and memory.”
