Substance addictions and suicidal thoughts and behaviors: Evidence from a multi-wave epidemiological study.

Substance addiction (SA) is a risk factor of suicidal thoughts and behaviors (STB), although it is still unclear which SAs are reliably associated with increased risk for suicidal ideation, planning, and attempt. The current study aimed to meet this goal using data from the National Survey on Drug Use and Health (NSDUH) referring to years from 2008 to 2020. The information extracted included sociodemographic and contextual information, eleven SAs (e.g., nicotine, alcohol, marijuana, cocaine, pain relievers, heroin, inhalants, hallucinogens, sedatives, stimulants, and tranquillizers), and STB. The analysis revealed that SAs for alcohol, pain relievers, marijuana, and cocaine were stable and reliable predictors for STB (e.g., suicidal ideation, planning, and attempt), while cocaine was not a stable predictor for suicide attempt. The selected SAs model showed a greater predictive accuracy than only sociodemographic and contextual factors as well as not selected SAs. Moreover, selected SAs showed comparable predictive accuracy to the full model. Furthermore, SA to alcohol showed to be an extremely effective predictor of STB, having a comparable predictive accuracy to all the other ten SAs together. In conclusion, SAs to pain relievers, alcohol, marijuana, and cocaine can be considered as important risk factors for concurrent STB.