Substance Use, Depression, and Suicide Risk: Findings from a Propensity-Weighted National Study

Background: In 2023, approximately 48.5 million Americans were affected by a substance use disorder, a key risk for suicide and suicidal ideation—including thoughts, attempts, and planning. Individuals with health conditions are also at significantly higher risk for suicide. Despite, the association linking a substance use disorder and major depressive episodes to such suicide risk is not fully explored. While mental health and substance use disorders are well-established risk factors, less is known about how systemic factors—like insurance coverage—may buffer or intensify this risk. Moreover, many individuals lacked consistent access to behavioral health care. This study explores the combined effects of SUD and Major Depressive Episodes (MDE) on suicide risk and investigates whether health insurance coverage moderates these relationships.

Methods: Data were drawn from the 2023 National Survey on Drug Use and Health (n=43,393). Logistic regression was applied to investigate the associations linking substance use disorder and major depressive episodes to suicide risk, adjusted for sociodemographic characteristics (i.e., age, sex/race, education, income, and insurance status). To strengthen causal inferences and mitigate selection bias, generalized propensity score weighting was applied to the logit model. To strengthen causal inferences and mitigate selection bias, generalized propensity score weighting was applied to the logit model. Weighted logistic regressions were then constructed to estimate both the average treatment effect (ATE) and the average treatment effect on the treated (ATT). Finally, interaction terms were included to examine whether insurance coverage moderated the relationship between SUD, MDE, and suicide risk.

Results: Among respondents, 10.1% reported mild SUD, and 4.5% each reported moderate or severe SUD. Most (70.4%) did not experience an MDE in the past year. Suicide-related behaviors were reported by 6.0% of the sample, with a notably higher prevalence (26.2%) among those with MDE compared to 3.70% among those without. Co-occurring SUD and MDE affected 14.8% of respondents.

Weighted logistic regression analysis revealed that both substance use disorder severity and major depressive episodes were significant predictors of suicide risk. Individuals with moderate (OR = 1.91, 95% CI [1.63, 2.24]) and severe major depressive episodes (OR = 2.47, 95% CI [2.14, 2.84]) were at elevated risk compared to those with no major depressive episodes. Depression remained the strongest predictor of suicide risk (OR = 9.44, 95% CI [8.58, 10.39]) even at the presence of substance abuse disorder. Postestimation showed these significant associations do not vary by health insurance status. All estimates were adjusted for sociodemographic characteristics using generalized propensity score weights.

Conclusion and Implications: Findings revealed the strong and compounding effects of mental health and substance use challenges on suicide risk. Depression remains the most dominant predictor, with risk further elevated when SUD was also present. The lack of significant moderation by insurance suggests that access to coverage alone may not be sufficient to reduce suicide risk. These results emphasize the importance of integrated, trauma-informed behavioral health care that accounts for both clinical and social risk factors.

Keywords: suicide risk, substance use disorder, major depressive episode, insurance, socioeconomic factors.