Subgroup differences in PTSD symptom presentations: A latent class analysis

Abstract

Posttraumatic stress disorder (PTSD) is a highly heterogeneous disorder (Galatzer-Levy & Bryant, 2013). Mixture modeling has been used to identify homogeneous subgroups of individuals based on patterns of PTSD symptom expression. However, most of these studies are based on DSM-IV rather than DSM-5 PTSD criteria. In addition, these studies employ different indicators of latent class membership, which contributes to variability in the number and nature of latent classes identified. Additionally, there is relatively limited construct validity evidence of identified latent classes. To address these limitations, a latent class analysis (LCA) of DSM-5 PTSD symptoms was conducted in a sample of undergraduate students (N = 322) who met criteria for a subthreshold diagnosis of PTSD. The current study aimed to replicate and extend findings from the limited number of LCAs of DSM-5 PTSD criteria and examine how resulting classes meaningfully differ in external correlates. Findings revealed a three-class solution: Low Anhedonia/Externalizing Behaviors (EB), Moderate Symptoms, and High Symptoms of PTSD. Relative to the other classes, the High Symptoms class was characterized by elevated anxiety and somatic symptoms on the Personality Assessment Inventory (PAI; Morey, 1991). Relative to the Low Anhedonia/EB, the Moderate Symptoms class was characterized by numerous psychopathology domains, including depression and borderline personality traits. Results from this study suggest that, beyond classes characterized by similar PTSD symptom severity across symptoms, some individuals with similar overall PTSD symptom severity differed based on depressive symptom characteristics. Implications and future directions are discussed.