Exposure to volatile organic compounds and suicidal ideation: Insights from a US population-based study

Background: Exposure to volatile organic compounds (VOCs) has been increasingly linked to mental health disorders, but the relationship between VOCs exposure and suicidal ideation (SI) remains unclear. This study aims to investigate the link between VOCs exposure and the prevalence of SI. Methods: We analyzed data from 6966 participants in the 2005-2020 National Health and Nutrition Examination Survey. SI was assessed using the ninth item of the Patient Health Questionnaire-9. Key urinary metabolites of VOCs (mVOCs) associated with SI were identified using elastic net regression models. Multivariate logistic regression and restricted cubic spline were used to explore associations between individual mVOCs and SI. To evaluate the impact of mVOCs mixtures on SI, we applied Environmental Risk Score and Weighted Quantile Sum models. Mediation analysis was conducted to determine whether inflammation and oxidative stress pathways contribute to the observed associations. Results: Among the participants, 253 reported SI. Across various models, only the urinary N-Acetyl-S-(2-cyanoethyl)-L-cysteine (CYMA) consistently showed a significant linear association with SI. Mixture analyses indicated a significant positive association between mVOCs mixtures and SI prevalence. Mediation analysis suggested that inflammation and oxidative stress are unlikely to be the primary mechanisms linking mVOCs exposure to SI. Conclusion: This study provides the first epidemiological evidence of an association between mVOCs exposure and SI. CYMA was identified as the most critical mVOCs influencing SI. The findings suggest that the link between mVOCs exposure and SI does not primarily involve inflammation or oxidative stress pathways.