Immature defense mechanisms mediate the relationship between childhood trauma and onset of bipolar disorder.

BACKGROUND

Accumulating evidence has converged to suggest that childhood trauma may contribute to bipolar disorder (BD). This study aimed to investigate the patterns of childhood trauma among patients with bipolar I (BD-I) and bipolar II (BD-II) disorders, according to DSM-IV and in contrast with healthy volunteers. We also explored whether the relationship between childhood trauma and onset of bipolar disorder is mediated by immature defense mechanisms.

METHODS

Participants were patients with BD-I (n=44) and BD-II (n = 42), and healthy controls (HCs, n = 43). Childhood traumatic experiences and defense mechanisms were assessed by the Childhood Trauma Questionnaire (CTQ) and the Defense Style Questionnaire (DSQ), respectively.

RESULTS

BD patients experienced more severe childhood trauma than HCs. Physical neglect sub-score and total score of the CTQ had both direct and indirect effects on the diagnosis of BD-I, and an immature defense style mediated the indirect effects. The diagnosis of BD-II was mainly related to the physical neglect and emotional abuse subs-core and total score of the CTQ, as mediated by the immature defense mechanisms. BD-I and BD-II significantly differed in the emotional abuse sub-score of the CTQ.

CONCLUSIONS

Physical neglect sub-score and total score of the CTQ were associated with the diagnosis of BD (both BD-I and BD-II), as mediated by an immature defense style. Furthermore, emotional abuse might be an important risk factor for BD-II compared to BD-I. These findings may inform risk reduction and psychosocial intervention strategies to prevent and treat patients with bipolar disorders.