title: Gray matter volume alterations related to trait dissociation in PTSD and traumatized controls.
abstract: OBJECTIVE
  This study used voxel-based morphometry (VBM) to investigate brain structural alterations related to trait dissociation and its relationship with post-traumatic stress disorder (PTSD).
  
  
  METHODS
  Thirty-two subjects either developing (N = 15) or non-developing (N = 17) PTSD underwent MRI scanning and were assessed with the Dissociative Experience Scale (DES), subscales for pathological (DES-T) and non-pathological trait (DES-A) dissociation, and other clinical measures. Gray matter volume (GMV) was analyzed using VBM as implemented in SPM. PTSD and non-PTSD subjects were compared to assess brain alterations related to PTSD pathology, whereas correlation analyses between dissociation measures and GMV were performed on the whole sample (N = 32), irrespective of PTSD diagnosis, to identify alterations related to trait dissociation.
  
  
  RESULTS
  As compared to traumatized controls, PTSD subjects showed reduced GMV in the prefrontal cortex, hippocampus and lingual gyrus. Correlations with dissociation measures (DES, DES-T, and DES-A) consistently showed increased GMV in the medial and lateral prefrontal, orbitofrontal, parahippocampal, temporal polar, and inferior parietal cortices.
  
  
  CONCLUSIONS
  PTSD and dissociation seem to be associated with opposite volumetric patterns in the prefrontal cortex. Trait dissociation appears to involve increased GMV in prefrontal, paralimbic, and parietal cortices, with negligible differences between pathological and non-pathological dissociation.
authors.affiliation: Neuroimaging Laboratory, Santa Lucia Foundation, Rome, Italy. davidenardo@gmail.com
authors.forename: D
authors.initials: D
authors.lastname: Nardo
authors.forename: G
authors.initials: G
authors.lastname: Högberg
authors.forename: R A
authors.initials: RA
authors.lastname: Lanius
authors.forename: H
authors.initials: H
authors.lastname: Jacobsson
authors.forename: C
authors.initials: C
authors.lastname: Jonsson
authors.forename: T
authors.initials: T
authors.lastname: Hällström
authors.forename: M
authors.initials: M
authors.lastname: Pagani
mesh_terms: D000328:Adult; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D008960:Models, Psychological; D009929:Organ Size; D017063:Outcome Assessment, Health Care; D017397:Prefrontal Cortex / Q000473:pathology / Q000503:physiopathology; D011569:Psychiatric Status Rating Scales; D011581:Psychological Tests; D013313:Stress Disorders, Post-Traumatic / Q000175:diagnosis / Q000503:physiopathology / Q000523:psychology
keywords: Dissociative Experience Scale; gray matter volume; post-traumatic stress disorder; trait dissociation; voxel-based morphometry (VBM)