Childhood trauma and depressive symptoms in bipolar disorder: A network analysis

Background: Childhood trauma is related to an increased number of depressive episodes and more severe depressive symptoms in bipolar disorder. The evaluation of the networks of depressive symptoms—or the patterns of relationships between individual symptoms—among people with bipolar disorder with and without a history of childhood trauma may assist in further clarifying this complex relationship. Methods: Data from over 500 participants from the Heinz C. Prechter Longitudinal Study of Bipolar Disorder were used to construct a series of regularised Gaussian Graphical Models. The networks of individual depressive symptoms—self-reported (Patient Health Questionnaire—9; n = 543) and clinician-rated (Hamilton Depression Rating Scale—17; n = 529)—among participants with bipolar disorder with and without a history of childhood trauma (Childhood Trauma Questionnaire) were characterised and compared. Results: Across the sets of networks, depressed mood consistently emerged as a central symptom (as indicated by strength centrality and expected influence); regardless of participants' history of childhood trauma. Additionally, feelings of worthlessness emerged as a key symptom in the network of self-reported depressive symptoms among participants with—but not without—a history of childhood trauma. Conclusion: The present analyses—although exploratory—provide nuanced insights into the impact of childhood trauma on the presentation of depressive symptoms in bipolar disorder, which have the potential to aid detection and inform targeted intervention development.