Substance use and deaths by suicide: A latent class analysis of the National Violent Death Reporting System

Substance use is strongly associated with suicide completions. However, little is known about the patterns of substances used in suicide deaths. The purpose of this analysis is to determine latent classes of toxicology-reported substances among individuals who completed suicide. The sample consists of suicide victims in the National Violent Death Reporting System (NVDRS) during years 2003-2017 (n = 202,838). Toxicology reports were used to construct latent class analyses of substance use among suicide victims. Correlates for latent class membership included sex, race/ethnicity, previous experiences of child abuse, homelessness, and intimate partner violence (IPV) victimization. The majority of suicide victims were male (77.7%), straight/heterosexual (99.5%) and white (88.3%). The final unconditional model yielded a four-class model, including a "No substance/single substance use" class, an "Alcohol and other substance" class, a "Marijuana and other substance" class, and an "Opiate use" class. Compared to the reference class of "No substance/single substance," females were more likely than males to be classified in the "Alcohol and other substance" class, the "Multi-substance use" class, and the "Opiate use" class. Homelessness was associated with classification in the "Marijuana and other substance" class and the "Opiate use" class compared to the "No substance/single substance" class. IPV was associated with both polysubstance use classes ("Alcohol plus other substance" and "Marijuana plus other substance") along with the "Opiate use" class compared to the "No substance/single substance" class. These classes highlight profiles of suicide descendants and emphasize the importance of polysubstance use prevention among females, homeless individuals, and those who experience IPV.