Cannabis-Related Suicide ED Visits Stayed Stable Two Years After Canadian Legalization | Research

The takeaway

The profile of patients presenting to Canadian EDs with both suicidal ideation and cannabis use remained stable from immediately post-legalization to two years later, though repeat visits for suicidality increased in the earlier cohort.

emergency medicine clinicians, cannabis policy researchers, suicide prevention professionals

What the researchers found

The number of ED encounters and suicidality-related ED encounters following the index visit were significantly higher in the immediate post-legalization cohort compared to the two-years-later cohort. However, the overall patient profile remained stable despite increased cannabis use in the general population. Personality disorders were associated with repeat cannabis-related ED visits.

Why it matters

A key concern about cannabis legalization is whether it would increase suicide-related presentations. This study from Canada provides real-world data suggesting the patient population remained stable even as legal access expanded.

The numbers in context

Two cohorts compared across matched 6.5-month periods. Significantly more follow-up ED visits in the early post-legalization cohort (t=2.05, p=0.042). Significantly more suicidality-related follow-up ED visits in the early cohort (t=2.23, p=0.027). Personality disorders associated with repeat visits.

How the study worked

Retrospective chart review comparing two cohorts of patients presenting to EDs with suicidal ideation/attempts and cannabis use: October 2018-April 2019 (immediately post-legalization) and October 2020-April 2021 (two years later). ED healthcare usage tracked for 2 years before and after index encounter.

What this study cannot tell us

Retrospective chart review with limited sample sizes. Only two EDs. Cannot establish causation between cannabis use and suicidality. COVID-19 pandemic overlapped with the second cohort, potentially confounding results. Cannabis use was self-reported during ED visits.

How to read the evidence

Retrospective chart review with statistical analysis and longitudinal tracking, but small sample, two sites, and COVID confounding limit evidence to moderate.

When this study was published

Data from October 2018 to April 2021, spanning Canadian cannabis legalization.

The bigger picture

The stability of the patient profile despite rising population-level cannabis use suggests that legalization may not be dramatically changing who presents with co-occurring suicidality and cannabis use, though the early post-legalization period showed more repeat visits.

Questions still open

Did the COVID-19 pandemic affect the second cohort's ED utilization patterns?
Would longer post-legalization follow-up reveal emerging trends?

Common questions

Did cannabis legalization in Canada increase suicidal ED visits?

The patient profile remained stable over two years despite increased general population cannabis use. However, the immediate post-legalization cohort had more repeat ED visits for suicidality.

Does cannabis cause suicidal thoughts?

This study examined co-occurrence, not causation. It tracked patients who presented with both suicidal ideation and cannabis use but could not determine whether cannabis contributed to their suicidality.

Read the original research

Understanding the role of cannabis in patients with suicidal ideation presenting to the emergency department: systematic chart review.

BJPsych open, 11(5), e199

View on PubMed ↗Publisher’s paper ↗

Citation

Simmons, Maria; Crocker, Candice E; Fisher, Derek; Stewart, Sherry H; Emsley, Jason G; Abidi, Sabina; Carter, Alix; Calkin, Cynthia; Yakovenko, Igor; Magee, Kirk; Tibbo, Philip G. (2025). Understanding the role of cannabis in patients with suicidal ideation presenting to the emergency department: systematic chart review.. BJPsych open, 11(5), e199. https://doi.org/10.1192/bjo.2025.10776