A Distinction Without a Difference? A Multi-Method Approach to Understanding PTSD and Depression Symptom Overlap Among Disaster-Exposed Adolescents.

Among adolescents exposed to trauma, posttraumatic stress disorder (PTSD) and major depressive disorder (MDD) commonly co-occur. Despite the prevalence of comorbidity, the question of how PTSD and MDD are related and appropriate conceptual models for understanding their linkage in adolescence remains unclear. This study applies a multi-methodological approach to advance conceptual and theoretical understanding of the overlap between PTSD and MDD diagnoses/symptoms. We tested three methodological approaches with three distinct theoretical underpinnings on the structure of each disorder proposed in the literature: confirmatory factor analysis (CFA) with dimensional constructs, latent class analysis (LCA) with person-based categorical constructs, and network analysis with symptom-to-symptom associations. Across the three different analytical approaches, there was a significant overlap between PTSD and MDD. Overall, there was no compelling evidence for distinct boundaries between disorders among trauma-exposed adolescents. Instead, we found considerable evidence that the typical latent-construct-based conceptualizations, whether categorical or dimensional, may need revision.