Post-traumatic and dissociative symptoms as significant predictors of depression: Results from an international follow-up survey study

Yuan G. F., Reyes M. E. S., Jaya E. S., Mukhtar F., Lian A. E. Z., DERİN G., ...More

EUROPEAN JOURNAL OF TRAUMA & DISSOCIATION, vol.10, no.3, 2026 (ESCI, Scopus)

Abstract

Background: Depression is a leading global public health concern, with trauma and trauma-related symptoms increasingly recognized as important contributors to its onset and maintenance. It remains unclear which specific post-traumatic and dissociative symptoms most strongly predict subsequent depressive symptoms. Objectives: This longitudinal study addressed this gap by examining the predictive role of complex PTSD and dissociative symptoms on depressive symptoms over six months. Methods: Participants were 293 female mental health service users recruited internationally. They completed surveys at baseline and six-month follow-up. Measures included the Patient Health Questionnaire-9 (PHQ-9) for depressive symptoms, the International Trauma Questionnaire (ITQ) for ICD-11 complex PTSD symptoms, and the Multiscale Dissociation Inventory (MDI) for dissociative symptoms. Results: Controlling for baseline depression, age, education, and location, hierarchical multiple regression analysis revealed that baseline re-experiencing symptoms (beta = 0.135, p = .019) and depersonalization (beta = 0.187, p = .034) significantly and positively predicted follow-up depressive symptoms. Nevertheless, baseline avoidance was negatively associated with depressive symptoms (beta = -0.304, p = .043) at follow-up. Conclusions: These findings suggest that the trauma model of depression requires more research and replication. Re-experiencing, depersonalization, and avoidance might be important symptom-level targets for preventing and treating depression, but future research should replicate these patterns in larger and more diverse samples, examine the mechanisms linking trauma-related symptoms to depressive trajectories, and evaluate whether trauma-focused interventions reduce depressive symptoms in individuals with prominent re-experiencing and depersonalization.