Relationship Between Youth Conduct Problems and Adulthood Suicidality: Mediating Effects of Personality on Patients with Mood Disorders

Background: Identifying the relevant factors for suicidality in individuals with conduct problems is a public health concern, especially if they develop mood disorders. This study investigates the relationship between youth conduct problems and adulthood suicidality, and to further explore the mediating effects of personality on this relationship. Methods: : A retrospective cohort study was administered to 308 individuals aged 20-65 years, including psychiatric outpatients with mood disorders and healthy controls. The Composite International Diagnosis Interview was used to evaluate conduct problems in youth and suicidality (i.e., suicide plan and suicide attempt) in the past year. Personality traits were assessed using Eysenck Personality Questionnaire-Revised for extraversion and neuroticism. Multiple-mediator analysis was used to investigate the mediation effects of personality traits on the relationship between conduct problems and suicidality. Results: : The average age of enrolled participants was 31.6 years. 39.2% reported suicidality and 43.2% reported conduct problems in youth. Participants who were diagnosed with mood disorders (p < 0.001) and reported having conduct problems (p = 0.004) were associated with high suicidality. Multiple-mediator analysis showed that conduct problems in youth increased the risk of adulthood suicidality through the indirect effects of higher neuroticism (suicide plan: OR = 1.30, BCA 95% CI = 1.04–1.83; suicide attempt: OR = 1.27, BCA 95% CI = 1.05–1.66). Conclusion: The relationship between youth conduct problems and adulthood suicidality exerted minimal direct effect after personality traits were included in the model. The indirect effect of neuroticism might be a pivotal finding for designing proper intervention strategies to reduce the risk of suicide.