title: An investigation of PTSD's core dimensions and relations with anxiety and depression.
abstract: OBJECTIVE
  Posttraumatic stress disorder (PTSD) is highly comorbid with anxiety and depressive disorders, which is suggestive of shared variance or common underlying dimensions. The purpose of the present study was to examine the relationship between the latent factors of PTSD with the constructs of anxiety and depression in order to increase understanding of the co-occurrence of these disorders.
  
  
  METHODS
  Data were collected from a nonclinical sample of 186 trauma-exposed participants using the PTSD Checklist and Hospital Anxiety and Depression Scale. Confirmatory factor analyses were conducted to determine model fit comparing 3 PTSD factor structure models, followed by Wald tests comparing the relationships between PTSD factors and the core dimensions of anxiety and depression.
  
  
  RESULTS
  In model comparisons, the 5-factor dysphoric arousal model of PTSD provided the best fit for the data, compared to the emotional numbing and dysphoria models of PTSD. Compared to anxious arousal, the dysphoric arousal and numbing factors of PTSD were more related to depression severity. Numbing, anxious arousal, and dysphoric arousal were not differentially related to the latent anxiety factor.
  
  
  CONCLUSIONS
  The underlying factors of PTSD contain aspects of the core dimensions of both anxiety and depression. The heterogeneity of PTSD's associations with anxiety and depressive constructs requires additional empirical exploration because clarification regarding these relationships will impact diagnostic classification as well as clinical practice.
authors.affiliation: Department of Psychology.
authors.forename: Brianna M
authors.initials: BM
authors.lastname: Byllesby
authors.affiliation: Department of Psychology.
authors.forename: Tory A
authors.initials: TA
authors.lastname: Durham
authors.affiliation: Department of Psychiatry.
authors.forename: David
authors.initials: D
authors.lastname: Forbes
authors.affiliation: School of Psychology.
authors.forename: Cherie
authors.initials: C
authors.lastname: Armour
authors.affiliation: Department of Psychology.
authors.forename: Jon D
authors.initials: JD
authors.lastname: Elhai
mesh_terms: D001007:Anxiety; D001143:Arousal; D003863:Depression; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D008297:Male; D008960:Models, Psychological; D011569:Psychiatric Status Rating Scales; D013313:Stress Disorders, Post-Traumatic / Q000523:psychology*; D055815:Young Adult