An examination of the potential core symptoms of posttraumatic stress disorder: What is integral after removing general psychopathology & distress?

Abstract

Many confirmatory factor analyses (CFA) have examined the structure of posttraumatic stress disorder (PTSD) with some suggesting increased complexity (i.e., 6+ factors), while others suggesting a more refined structure (i.e., 2-factors). These competing PTSD structures may be due to conflation of non-trauma specific symptoms that have been added overtime. However, none of these studies examined if all symptoms being examined are specific to PTSD or potentially more related to general distress and psychopathology. The current study re-evaluated the structure of PTSD using bifactor exploratory factor analysis (EFA) to identify the construct's core symptoms. Data for EFA models were taken from a sample of Veterans (N = 694) attending outpatient therapy for PTSD and were cross-validated using CFA in a sample of 297 Veterans attending residential treatment. Clinician Administered PTSD Scale for DSM-5 (CAPS-5) at pre-treatment was used across sample. Factor analyses resulted in a 2-factor, bifactor model comprised of eight total items. Model fit was robust, RMSEA = 0 [0.000, 0.036]; robust CFI = 1; robust TLI = 1.017. The bifactor analytic approach captured what might be the core structure of PTSD, which were pathognomonic symptoms of PTSD (Factor one). A distinct second factor related to depression was also found. In identifying this structure, the model eliminates redundancies and lesser performing items and differentiates depressive reactions as potentially distinct and separate. Overall, these findings may assist in future research of PTSD by determining the unique elements of the construct within a veteran sample versus associated features, general psychological distress, and comorbid psychopathology.