Latent Factor Structure of DSM-5 Posttraumatic Stress Disorder: Evaluation of Method Variance and Construct Validity of Novel Symptom Clusters

The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) 4-factor model of posttraumatic stress disorder (PTSD) has demonstrated adequate fit in several confirmatory factor analysis (CFA) studies. Although several alternative measurement models have demonstrated better fit, there is no consensus yet on the best model, and newly proposed models lack sufficient construct validation. Notably, these studies have relied exclusively on questionnaire data, and thus their findings may be attributable to a method effect. This study examined the factor structure of DSM-5 PTSD symptoms using both questionnaire and interview data to determine the impact of assessment method on factor structure and construct validity of alternative model symptom clusters. Participants (N = 380) were veterans who completed the PTSD Checklist for DSM-5 (PCL-5; Weathers et al., 2013) and the Clinician-Administered PTSD Scale for DSM-5 (CAPS-5; Weathers et al., 2013). Fit was similar across models. However, the seven-factor Hybrid model (Armour et al., 2015) fit best. Limited evidence of a method effect was observed. Results of construct validity analyses were mixed; some of the newly proposed symptom clusters demonstrated hypothesized differential associations with external correlates, but others did not. These findings suggest that results of previous DSM-5 PTSD CFAs supporting the Hybrid model are not attributable to a method effect. However, observed limited difference in model fit and mixed construct validity evidence raise concerns regarding the value of parsing DSM-5 symptom clusters. Constructs implied by the new factors in the more complex measurement models of PTSD require greater explication and construct validation.