Cannabis Poisonings Among Older Adults Tripled After Legalization, Study Finds

The spread of cannabis legalization across the U.S. and other countries hasn't come without its fair share of issues. A new study out of Canada examined how older adults specifically have been dealing with cannabis poisonings related to the increased access to marijuana products in the country in recent years. 

The findings, published May 20 in the JAMA Internal Medicine journal, looked at the rate of emergency department visits for cannabis poisoning in older Canadian adults. The researchers used information from the Ontario Ministry of Health to determine the rates of emergency room visits for cannabis poisoning among older adults in the years before and after legalization. Only dried cannabis flower was permitted for sale between October 2018 and December 2019 with edibles joining the party in January 2020. The study examined pre-legalization numbers from January 2015 to September 2018 and legalization figures in both the flower-only and flower-and-edible periods up until December 2022. 

The scientists found some concerning contrasts between the pre- and post-legalization eras. In total throughout the entire eight-year study period, there were 2,322 emergency department visits for cannabis poisoning in older adults with an average age of 69. Compared with pre-legalization, the flower-only legalization period between late 2018 and 2019 saw a doubled rate of emergency department visits for cannabis poisoning; when edibles entered the mix in 2020, the rate of hospitalization was triple that of pre-legalization times. 

Part of this likely has to do with the fact that this isn't your parents' weed. "Cannabis today is very different than cannabis was as recently as the early '90s and mid '80s," study lead author Dr. Nathan Stall explained to CNN. "Today’s cannabis extracts contain as much as 30 times more THC. … Older adults who may not have used cannabis in decades and are now trying again in this post-legalization era may not be aware."

Cannabis poisoning isn't a fun experience, to say the least. Stall noted that symptoms may include confusion, psychosis, anxiety or panic attacks, rapid heartbeat, chest pain, nausea, and vomiting. Many of the unfamiliar might have a tougher time gauging their cannabis intake with edibles, possibly explaining the tripling of poisoning hospitalizations during the legalized edibles period. 

The study authors acknowledged that their research is "limited to emergency department visit data," and as such, "may underestimate the true magnitude of cannabis poisonings." 

"Our findings align with national U.S. data showing that edible cannabis accounts for an increasing proportion of cannabis poisoning in older adults. Overall, this study shows the health outcomes of cannabis legalization and commercialization for older adults and highlights the consequences associated with edible cannabis," the authors concluded in the study. "Jurisdictions with legalized cannabis should consider measures to mitigate unintentional exposure in older adults and age-specific dosing guidance."