Exploring the relationships between complex post-traumatic stress disorder and depression symptoms in the context of childhood maltreatment through network analysis

Background: Individuals with a history of childhood maltreatment commonly experience the cooccurrence of complex post-traumatic stress disorder (CPTSD) and depression, but the underlying mechanisms of their comorbidities remain unclear. Methods: We recruited 2740 college students, including 1366 who experienced childhood maltreatment to assess the co-occurrence network of CPTSD and depression symptoms. We constructed a Gaussian graphical model to visualize the associations between symptoms and a directed acyclic graph to explore inferred relationships among symptoms. Results: (1) We identified the following five subnetworks within the co-occurring network of CPTSD and depression symptoms: post-traumatic stress disorder (PTSD), disturbance in selforganization (DSO), depression with vegetative symptoms, depression with interpersonal problems, and lack of positive affect subnetworks. (2) Core symptoms, identified by their high expected influence, such as sadness, low spirits, and not feeling loved have the highest EI in the depression subnetwork, whereas failure, distant, avoiding clues, and avoiding thoughts have the highest EI in the DSO and PTSD subnetworks. Bridging symptoms in the childhood maltreatment network included failure, self-denial, startlement, and hyperactivity. (3) The inferred mechanism identified includes PTSD activating DSO, which subsequently triggers depression in the childhood maltreatment network. Limitations: This study involved a non-clinical sample. Conclusion: Our study contributes to a deeper understanding of the mechanisms of CPTSD and depression co-occurrence at a transdiagnostic level and has implications for better clinical interventions targeting influential symptoms.