Reconciling the differences between the King et al. (1998) and Simms et al. (2002) factor models of PTSD

Much of the debate surrounding the dimensionality of PTSD relates to three specific Hyperarousal symptoms (D1-D3) and whether they are appropriate indicators of one of two broad constructs that constitute PTSD: Dysphoria or Hyperarousal. This study addressed this issue by testing a series of confirmatory factor models to determine which factor, or factors, these symptoms measured the strongest. Data from individuals who satisfied the conditions for Criterion A of the diagnostic criteria for a DSM-IV diagnosis of PTSD (n = 12,467) in the 2004-2005 NESARC were used in the analysis. The results revealed that the D1-D3 symptoms were not clear indicators of either factor, but measured both Dysphoria and Hyperarousal. Two symptoms, however, loaded more highly on the Dysphoria, rather than Hyperarousal, factor. The present findings lend support to the factor model proposed by Simms et al. [Simms, L. J., Watson, D., & Doebbeling, B. N. (2002). Confirmatory factor analyses of posttraumatic stress symptoms in deployed and non-deployed veterans of the Gulf War. Journal of Abnormal Psychology, 111, 637-647] but also question the use of symptoms that are not unique indicators of specific factors.