title: Symptom structure of PTSD: support for a hierarchical model separating core PTSD symptoms from dysphoria.
abstract: BACKGROUND
  As of yet, no collective agreement has been reached regarding the precise factor structure of posttraumatic stress disorder (PTSD). Several alternative factor-models have been proposed in the last decades.
  
  
  OBJECTIVE
  The current study examined the fit of a hierarchical adaptation of the Simms et al. (2002) dysphoria model and compared it to the fit of the PTSD model as depicted in the Diagnostic and Statistical Manual for Mental Disorders, Fourth Edition (DSM-IV), a correlated four-factor emotional numbing, and a correlated four-factor dysphoria model.
  
  
  METHODS
  Data were collected using the Clinician-Administered PTSD Scale in a mixed-trauma sample of treatment-seeking PTSD patients (N=276).
  
  
  RESULTS
  All examined models provided superior fit to the three-factor model of DSM-IV. The hierarchical four-factor solution provided a better fit than competing models.
  
  
  CONCLUSIONS
  The present study provides empirical support for a conceptualization of PTSD that includes a higher-order PTSD factor that encompasses re-experiencing, arousal, and effortful avoidance sub-factors and a dysphoria factor.
authors.affiliation: Research Centre, Military Mental Healthcare, Utrecht, the Netherlands ; Department of Psychiatry, Rudolf Magnus Institute of Neuroscience, Utrecht University Medical Centre, Utrecht, the Netherlands.
authors.forename: Arthur R
authors.initials: AR
authors.lastname: Rademaker
authors.forename: Agnes
authors.initials: A
authors.lastname: van Minnen
authors.forename: Freek
authors.initials: F
authors.lastname: Ebberink
authors.forename: Mirjam
authors.initials: M
authors.lastname: van Zuiden
authors.forename: Muriel A
authors.initials: MA
authors.lastname: Hagenaars
authors.forename: Elbert
authors.initials: E
authors.lastname: Geuze