The symptom structure of posttraumatic stress disorder in the National Comorbidity Replication Survey

Previous research has provided mixed findings for the validity of various three- and four-factor models of posttraumatic stress disorder (PTSD) symptomatology. However, much of this research has been restricted to clinical samples rather than nationally representative community-based samples. The current study employed confirmatory factor analysis to evaluate the validity of three competing models of PTSD symptom structure using the DSM-IV-based National Comorbidity Replication Survey (part II of the NCS-R: N = 5692). Individuals with a lifetime diagnosis of PTSD (N = 588) were selected and symptom assessment was based on the World Health Organization Composite International Diagnostic Interview. Strong support was found for both the DSM-IV three-factor model and a four-factor model of PTSD symptoms by King et al. [King, D. W., Leskin, G. A., King, L. A., & Weathers, F. W. (1998). Confirmatory factor analysis of the clinician-administered PTSD scale: evidence for the dimensionality of posttraumatic stress disorder. Psychological Assessment,10, 90–96], a variation of the DSM-IV model in which avoidance and numbing are viewed as separate factors. There was some evidence, however, that the King et al. [King, D. W., Leskin, G. A., King, L. A., & Weathers, F. W. (1998). Confirmatory factor analysis of the clinician-administered PTSD scale: evidence for the dimensionality of posttraumatic stress disorder. Psychological Assessment,10, 90–96] model demonstrated a significantly superior fit over the DSM-IV three-factor model. Because this study provided support for both the DSM-IV three-factor model and the King et al., four-factor model of PTSD symptoms, further research is still necessary to provide more definitive conclusions in this area.