Individuals with an emergency department (ED) visit or hospitalization due to cannabis were at 23% and 72% greater risk of a new dementia diagnosis within five years compared to individuals with an ED visit or hospitalization for any other reason or the general population, a recent study revealed.

The study included 6 million adults ages 45 years or older from Ontario, Canada, who had no history of dementia when they entered the study cohort between 2008 and 2021. The individuals were followed until 2022. Over the course of the study, 16,275 (0.3%) individuals ages 45 years or older (60% men) had acute care due to cannabis.

The annual rate of people over 45 with a first-time acute-care visit for cannabis use increased more than five-fold over the study period, from 353 (6.9 per 100,000 individuals) in 2008 to 2,508 (37.6 per 100,000 individuals) in 2021. Increases were even larger among individuals 65+ years (26.7-fold increase).

A total of 5% and 19% of individuals ages 45 years or older with treatment for cannabis in acute care were diagnosed with dementia within 5 and 10 years, respectively, compared to 3.6% and 14.8% of those who underwent acute care for another reason, and 1.3% and 5.5% in the general population.

After adjusting for social factors, other mental health diagnoses, and chronic conditions, individuals with acute care due to cannabis were at 1.23 and 1.72-fold higher risk of a dementia diagnosis than individuals with all-cause acute care and the general population, respectively.

“These findings have important implications considering increasing cannabis use among older adults,” the authors concluded.

To read the abstract of the study, published in JAMA Neurology, click here