Changes in Post-Mortem Marijuana-Positive Toxicologies Among Youth Suicide Decedents, 2005-2015

Background and Purpose: Given increasing youth suicide rates and liberalization of marijuana use laws, this study examined post-mortem marijuana toxicology test results among suicide decedents aged 15-19 (youth) compared to those aged 20-29 (young adults).

Methods: Data were from the 2005-2015 National Violent Death Reporting System (N=6,002 decedents aged 15-19 and N=20,925 decedents aged 20-29). Following descriptive analysis, logistic regression models were used to test associations of marijuana-positive toxicologies with incident year, state in which injury/death incurred, interactions between incident year and state, and suicide means.  

Results: Marijuana was the most commonly substantiated substance among youth and the second most commonly substantiated substance, after alcohol, among young adults. The odds of a marijuana-positive toxicology among youth were 2.21 (95% CI=1.78-2.73) higher in 2012-2015 than in 2005-2011 and were 1.46 (95% CI=1.18-1.79) higher in states with marijuana legalization or decriminalization laws; however, the incident year x state interaction term was not significant, and only the main effect of incident year remained significant (AOR=1.86, 95% CI=1.34-2.59) in the interaction model. Among young adults, the main effects of incident year, state, and interaction effects (AROR=2.02, 95% CI=1.61-2.53) were all significant. For both age groups, the odds of a marijuana-positive toxicology were lower among decedents who used poisoning than firearms.

Conclusions and Implications: Liberalized marijuana policies do not appear to have influenced increases in marijuana-positive toxicologies among youth, but marijuana-positive rates were higher among those who died in recent years and by more violent/lethal means. Youth suicide prevention strategies should include monitoring marijuana use, education on marijuana’s harms, and substance use treatment.