Cannabis-Related Diagnoses Were Associated With 21% Higher Odds of Overdose in Emergency Department Patients

What the researchers found

Cannabis-related diagnosis was associated with 21% higher odds of overdose (aOR=1.21, p<0.05), similar to opioid-related diagnosis (aOR=1.14). Overdose odds were higher for ages 40-54 (aOR=1.37), Black patients (aOR=1.31), Hispanic patients (aOR=1.22), publicly insured (aOR=1.40), and those with mental health diagnoses (aOR=1.13). Female sex (aOR=0.78) and being married (aOR=0.69) were protective.

Why it matters

The association between cannabis-related diagnoses and overdose risk is important because cannabis itself rarely causes fatal overdose. This suggests cannabis use disorder may be a marker for polysubstance use and broader vulnerability to drug-related emergencies.

The numbers in context

13,477 adults with SRD in ED (2020-2023). Cannabis diagnosis: aOR=1.21 for overdose. Opioid diagnosis: aOR=1.14. Ages 40-54: aOR=1.37. Black: aOR=1.31. Hispanic: aOR=1.22. Public insurance: aOR=1.40. Mental health: aOR=1.13. Female: aOR=0.78 (protective). Married: aOR=0.69 (protective).

How the study worked

Cross-sectional study of 13,477 adults with substance-related diagnoses who had ED encounters at UCSD Health from 2020-2023. Bivariate and multiple logistic regression examined factors associated with overdose.

What this study cannot tell us

Cross-sectional design at one health system. Cannabis-related diagnosis does not mean cannabis caused the overdose. ICD-10 coding may not capture all substance use. Southern California population may not generalize. COVID-19 period (2020-2023) may have influenced patterns.

How to read the evidence

Moderate: large ED dataset with adjusted regression modeling, though single-center cross-sectional design limits generalizability and causal inference.

When this study was published

2025 study using 2020-2023 ED data.

The bigger picture

This finding is consistent with cannabis use disorder as a risk marker rather than a direct cause of overdose. It suggests people with CUD may benefit from comprehensive substance use screening and harm reduction interventions during ED visits.

Questions still open

• Is cannabis use disorder a risk factor for polysubstance use that leads to overdose? Would screening for CUD in ED settings help identify patients at higher overdose risk? Are the racial disparities driven by systemic factors or differential exposure?

Common questions

Read the original research

Sociodemographic and clinical characteristics associated with overdose among patients with a substance-related diagnosis in the emergency department of Southern California.

Harm reduction journal, 22(1), 86

Citation

Maila, Brian; Zúñiga, María Luisa; Marienfeld, Carla. (2025). Sociodemographic and clinical characteristics associated with overdose among patients with a substance-related diagnosis in the emergency department of Southern California.. Harm reduction journal, 22(1), 86. https://doi.org/10.1186/s12954-025-01233-9

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