Acute Care for Cannabis Use Increases Risk for Subsequent New Dementia Diagnosis

Compared with those with all-cause hospital-based care and the general population, risk increased for those with cannabis use-based care

By Lori Solomon HealthDay Reporter

FRIDAY, April 18, 2025 (HealthDay News) — Individuals seeking acute care for cannabis use have an increased risk for a new dementia diagnosis compared with those with all-cause hospital-based care or the general population, according to a study published online April 14 in JAMA Neurology.

Daniel T. Myran, M.D., M.P.H., from the University of Ottawa in Ontario, Canada, and colleagues investigated the association between emergency department visits or hospitalizations (acute care encounters) due to cannabis and future dementia diagnosis. The analysis included health administrative data from 6 million individuals (aged 45 to 105 years living in Ontario between 2008 and 2021) without a diagnosis of dementia at baseline.

The researchers found that annual rates of incident acute care due to cannabis use increased fivefold in individuals aged 45 to 64 years (from 10.16 to 50.65 per 100,000) and increased 26.7-fold in individuals aged 65 years and older (from 0.65 to 16.99 per 100,000) during the study period. Individuals with incident acute care due to cannabis use had a 1.5-fold and 3.9-fold increased five-year risk for dementia diagnosis versus individuals with all-cause acute care and the general population of matched adults (absolute rates of dementia diagnosis: 5.0 percent for cannabis-related acute care, 3.6 percent for all-cause acute care, and 1.3 percent in the general population). Individuals with acute care due to cannabis use remained at elevated risk relative to those with all-cause acute care (adjusted hazard ratio [aHR], 1.23) and the general population (aHR, 1.72) when adjusting for sociodemographic factors and chronic health conditions. However, dementia risk was lower for individuals with acute care due to cannabis use than those with acute care due to alcohol use (aHR, 0.69).

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

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