Why we think it’s important 

This article highlights the significant public health implications of cannabis legalization, particularly for older adults who are at increased risk of adverse effects from cannabis poisoning. By examining the rise in emergency department visits post-legalization, the study underscores the need for targeted safety measures and age-specific guidelines to protect this vulnerable population. 


In recent years, the legalization of cannabis has prompted significant public health scrutiny, particularly concerning its impact on vulnerable populations such as older adults. Canada’s phased legalization, starting with dried cannabis in 2018 and extending to include edibles in 2020, provided a unique opportunity to study the effects of policy changes on health outcomes in this demographic. 

Study Methodology 

The study, conducted as a retrospective, population-based cross-sectional analysis, utilized administrative health data from Ontario, Canada. This approach allowed researchers to track emergency department (ED) visits related to cannabis poisoning among older adults (aged ≥65 years) across three distinct policy periods: pre-legalization, legalization of dried cannabis only, and legalization of both dried and edible cannabis. The analysis was robustly designed under the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) reporting guideline, ensuring transparency and adherence to rigorous reporting standards. The STROBE reporting guideline provides a 22-item checklist to ensure transparent, complete, and accurate reporting of cohort, case-control, and cross-sectional studies. It covers essential aspects like study design, participants, variables, data sources, bias, statistical methods, and results, facilitating the interpretation and replication of observational research. 

Key Findings 

Over the 8-year study period, the research identified 2,322 ED visits for cannabis poisoning among older adults in Ontario. Notably, the rates of ED visits significantly increased during the periods following cannabis legalization: from 5.8 visits per 100,000 person-years pre-legalization to 15.4 during the initial legalization phase and further to 21.1 during the period when edible cannabis became legally available. These findings were adjusted for various factors including age, sex, rurality, income, and comorbidities like alcohol intoxication, cancer, and dementia. 

Discussion and Implications 

The study’s findings underscore several critical points regarding the legalization of edible cannabis and its impact on older adults’ health: 

  • Increased Risk: The introduction of edible cannabis was associated with a substantial rise in ED visits for cannabis poisoning among older adults, highlighting increased accidental ingestion and accessibility concerns. 
  • Vulnerabilities: Older adults are particularly susceptible to adverse effects due to age-related physiological changes, polypharmacy, and potential drug interactions, factors not always adequately considered in cannabis consumption. 
  • Policy Considerations: The study calls for targeted policy interventions, including age-specific dosing guidelines and enhanced public education, to mitigate unintentional cannabis exposure in this demographic. 

Limitations and Future Directions 

Acknowledging its limitations, such as the reliance on ED data which may underestimate total incidents and the inability to establish direct causation between edible cannabis availability and ED visits, the study suggests avenues for further research. Future studies could explore long-term health outcomes, patient-reported experiences, and broader societal impacts beyond the ED setting. 


In conclusion, “Impact of Edible Cannabis Legalization on Emergency Department Visits for Cannabis Poisoning in Older Adults in Ontario, Canada” provides compelling evidence of the health consequences associated with cannabis policy changes. It highlights the need for nuanced regulatory frameworks and targeted health interventions to safeguard older adults amidst evolving cannabis legislation. As jurisdictions worldwide grapple with cannabis legalization, this study serves as a critical reference for policymakers and healthcare providers aiming to balance access with public health considerations, especially for vulnerable populations. 

Overall, the research contributes significantly to our understanding of cannabis policy impacts on older adults’ health and underscores the importance of proactive measures to mitigate unintended health risks in an increasingly legalized cannabis landscape.  



Stall NM, Shi S, Malikov K, et al. Edible Cannabis Legalization and Cannabis Poisonings in Older Adults. JAMA Intern Med. Published online May 20, 2024. doi:10.1001/jamainternmed.2024.1331