Feelings of worthlessness, traumatic experience, and their comorbidity in relation to lifetime suicide attempt in community adults with major depressive disorder

Background Major depressive disorder (MDD) and traumatic experience are independent risk factors for lifetime suicide attempt (LSA). However, the relationships between trauma history and depressive symptomatology as they relate to LSA are not fully understood. Methods A total of 12,532 adults, randomly selected through one-person-per-household method, completed a face-to-face interview using the Korean version of Composite International Diagnostic Interview (K-CIDI) and a questionnaire for LSA (response rate 80.2%). Results Among 825 subjects with MDD, 141 subjects reported an LSA (17.1%). LSAs were significantly greater in those who had experienced any trauma than in those who had not (χ²=34.66, p<0.0001). Multivariate logistic regression showed that only feelings of worthlessness were significantly associated with LSA among 20 depression symptoms in individuals with MDD (AOR=3.08, 95% CI 1.70-5.60). Feelings of worthlessness was associated with LSA in those who had experienced serious trauma (AOR=5.02, 95% CI 3.35-7.52), but not in those who had not. Serious traumas associated with LSA included military combat, witnessing a violent crime, rape or sexual assault, a bad beating, being threatened by others, and learning about traumas to others. Serious trauma showed no significant association with LSA in those who did not have feelings of worthlessness. PTSD was a comorbidity that showed the highest odds ratio with LSA in individuals with MDD. Conclusions Feelings of worthlessness are more strongly associated with LSA than other depression symptoms in individuals with MDD, and it is significantly associated with LSA in those who experienced serious trauma but not in those who did not.