Suicidal Thoughts and Behaviors Among US Adolescents: The Cumulative Effects of Polysubstance Use Behaviors.

Background:  The linkage between substance use and youth suicidality is less developed due to the predominant focus on certain types of substances (e.g., alcohol consumption, prescription opioid misuse). This study examines polysubstance use and its mutual impact on suicidal thoughts and behaviors among US adolescents. Methods:  Data from 2019 Youth Risk Behavior Survey were utilized. Associations between the concurrent use of five substances (cigarette, e-cigarette, alcohol, marijuana, and prescription opioid) and suicidality (suicidal thoughts, suicide plans, and suicide attempts) were measured by logistic regression models. The combined effect of polysubstance use on suicidality was further assessed by structural equation modeling. Results:  About two in five (42.1%) adolescents used at least one type of substances in the past month and one in seven (13.5%) used three or more types concurrently (polysubstance use). Adolescents with polysubstance use behaviors were three to five times more likely to experience suicidal thoughts (OR=3.8, p  < 0.05), make a suicide plan (OR=3.5, p  < 0.05), or attempt suicide (OR=4.6, p  < 0.05) than non-users. In the final structural model, polysubstance use and suicidality were significantly correlated with each other (β=0.37, p  < 0.05). Collectively, polysubstance use explained about 14% of variance in youth suicidality. Conclusions:  Polysubstance use shows a significant impact on youth suicidality. School-based health centers and educational programs are recommended to reduce substance use and suicidal behaviors among adolescents. Accessible mental health services and targeted treatments are needed for polysubstance users to mitigate their risk of suicide.