A new study from Canada has found that middle-aged and older adults who sought hospital or emergency room care for cannabis use were nearly twice as likely to develop dementia within five years compared to similar individuals in the general population. The research, which analyzed medical records from over six million people in Ontario between 2008 and 2021, also indicated that the risk of developing dementia was 23 percent higher among cannabis users when compared to adults seeking care for other issues.
The study did not specify the amount of cannabis used by the participants and does not establish a direct causal link between cannabis use and dementia. However, Dr. Daniel T. Myran, the study’s lead author and an assistant professor of family medicine at the University of Ottawa, emphasized the need for further investigation into this issue. He noted that understanding whether cannabis use, particularly heavy and chronic use, causes dementia is a complex question that cannot be answered with a single study.
Dr. Myran’s previous research has indicated that individuals with cannabis use disorder died at nearly three times the rate of those without the disorder over a five-year period. He has also reported an increase in schizophrenia and psychosis cases linked to cannabis use disorder since legalization in Canada. The latest findings about dementia add to the growing body of research examining the effects of regular or heavy cannabis use on cognitive functions.
The study’s strengths lie in its large sample size and the ability to track participants over time, ensuring they did not have a dementia diagnosis when they first sought cannabis-related care. Madeline Meier, an associate professor of psychology at Arizona State University who was not involved in the study, pointed out that the researchers successfully ruled out pre-existing dementia at the onset of cannabis use. She stressed that this study signals serious concerns about the potential risks of cannabis use.
Dr. Meier’s own research has linked cannabis use to neuropsychological decline over time. She cautioned against the perception that cannabis is harmless or solely beneficial for medical purposes. According to her, the study indicates an association that should prompt individuals to consider the potential risks involved. Additionally, the study found that those seeking care for alcohol use were even more likely to receive a dementia diagnosis than cannabis users.
The trend of increasing cannabis use among seniors is also notable. The study highlighted that medical visits related to cannabis use surged more than fivefold among adults aged 45 and older from 2008 to 2021. For those aged 65 and older, the increase was nearly 27-fold, reflecting a significant shift in the demographics of cannabis users.
