Persistence and clinical consequences of post-traumatic and dissociative symptoms in people with depressive symptoms: a one-year follow-up study

Background: Recent studies found that post-traumatic and dissociative symptoms are common in people with depressive symptoms. Although a trauma-related subtype of depression has been proposed, little is known about the persistence and clinical consequences of these symptoms. Objective: This one-year follow-up study investigated the persistence and clinical consequences of post-traumatic and dissociative symptoms in people with depressive symptoms. Methods: We analyzed longitudinal data from an international sample of people self-reporting depressive emotions (N = 152) (mean Patient Health Questionnaire-9 score = 17.27; SD = 6.31). Results: More than half (58.4%) of participants with baseline post-traumatic stress disorder (PTSD) still met the criteria for PTSD after one year. Participants with dissociative symptoms at baseline were significantly more likely to report lifetime psychiatric hospitalization (31.2% vs 14.7%), past-year use of psychiatric hospitalization (10.4% vs 0%) and emergency services (16.9% vs 4%) than those without dissociative symptoms. All post-traumatic and dissociative symptom clusters were cross-sectionally (r =.286 to.528, p <.001) and longitudinally (r =.181 to.462, p <.001) correlated with depressive symptoms. A sense of current threat (β =.146, p <.05) and negative self-concept (β =.173, p <.05) at baseline significantly predicted depressive symptoms after one year. Conclusions: These findings contribute to the increasing body of knowledge regarding the PTSD/dissociation-depression comorbidity. Given their persistence and clinical consequences, we recommend that post-traumatic and dissociative symptoms be regularly screened for in clinical settings. The existence of a possible trauma-related subtype of depression should receive more attention in both research and clinical practice.