Cannabis detection in postmortem toxicology among suicide decedents in the Federal District, Brazil, 2009-2019.

Lyrio A.; Souza E.; de Andrade Gomes J.; de Carvalho D.; de Moraes Rego E.; Batista J.; Dos Santos Conceição S.; Gomes-Filho I.; da Cruz S.; Figueiredo A. et al. · Journal of affective disorders · 2026

**Background & Methods** This population-based cross-sectional study analyzed 1,164 suicide deaths in the Federal District, Brazil (2009-2019) with complete toxicological data extracted from death certificates, police reports, and Legal Medicine Institute postmortem examinations. Poisson regression with robust variance was used to calculate crude and adjusted prevalence ratios (PR) with 95% confidence intervals to identify factors associated with postmortem cannabis detection. **Key Findings** • Cannabis was detected in 7.8% of suicide decedents. Independent associations with cannabis positivity included adolescent age (12-17 years: aPR = 4.61; 95%CI: 1.31-16.17), prior criminal offense record (aPR = 1.71; 95%CI: 1.11-2.63), and the period 2016-2019 (aPR = 2.83; 95%CI: 1.20-6.67), suggesting increasing detection over time. • Concurrent cocaine detection was strongly associated with cannabis positivity (aPR = 2.57; 95%CI: 1.67-3.96), indicating polysubstance use patterns among suicide decedents. • Cannabis detection clustered within high-vulnerability subgroups characterized by younger age, criminal history, and concurrent substance use, suggesting a distinct toxicological profile in this population. **Dosage & Administration** Not reported. **Safety & Adverse Effects** Not reported. This postmortem toxicology study does not address acute effects or clinical safety outcomes. **Evidence Quality** This study has several limitations relevant to interpretation. As a cross-sectional postmortem analysis, it cannot establish causality between cannabis use and suicide. The 7.8% detection rate likely underestimates actual cannabis prevalence due to postmortem degradation and variable testing protocols across the 10-year period. Selection bias may exist if toxicological testing was not uniformly applied to all suicide cases. The study represents a single geographic region (Federal District, Brazil) with limited generalizability to other populations. Additionally, postmortem toxicology cannot distinguish between acute intoxication at time of death versus chronic use. Despite these limitations, the study provides valuable epidemiological data on substance use patterns in suicide decedents and identifies vulnerable subgroups for targeted prevention efforts. The findings warrant further investigation into the relationship between cannabis, polysubstance use, and suicide risk in adolescents and individuals with criminal histories.

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