title: Cortical thickness reduction in combat exposed U.S. veterans with and without PTSD.
abstract: We investigated the extent of cortical thinning in U.S. Veterans exposed to combat who varied in the severity of their posttraumatic stress disorder (PTSD) symptoms. In addition, we explored the neural correlates of PTSD symptom dimensions and the interactive effects of combat exposure and PTSD upon cortical thickness. Sixty-nine combat exposed Veterans completed high-resolution magnetic resonance imaging (MRI) scans to estimate cortical thickness. The Clinician Administered PTSD Scale (CAPS) and Combat Exposure Scale (CES) assessments were completed to measure current PTSD and historical combat severity, respectively. PTSD symptom dimensions (numbing, avoidance, reexperiencing, anxious arousal, and dysphoric arousal) were studied. Vertex-wise whole cerebrum analyses were conducted. We found widespread negative correlations between CAPS severity and cortical thickness, particularly within the prefrontal cortex. This prefrontal correlation remained significant after controlling for depression severity, medication status, and other potential confounds. PTSD dimensions, except anxious arousal, negatively correlated with cortical thickness in various unique brain regions. CES negatively correlated with cortical thickness in the left lateral prefrontal, regardless of PTSD diagnosis. A significant interaction between CES and PTSD diagnosis was found, such that CES negatively correlated with cortical thickness in the non-PTSD, but not in the PTSD, participants. The results underscore the severity of cortical thinning in U.S. Veterans suffering from high level of PTSD symptoms, as well as in Veterans with no PTSD diagnosis but severe combat exposure. The latter finding raises considerable concerns about a concealed injury potentially related to combat exposure in the post-9/11 era.
authors.affiliation: National Center for PTSD - Clinical Neurosciences Division, US Department of Veterans Affairs, West Haven, CT, United States; Department of Psychiatry, Yale University School of Medicine, New Haven, CT, United States.
authors.forename: Kristen M
authors.initials: KM
authors.lastname: Wrocklage
authors.affiliation: National Center for PTSD - Clinical Neurosciences Division, US Department of Veterans Affairs, West Haven, CT, United States; Department of Psychiatry, Yale University School of Medicine, New Haven, CT, United States.
authors.forename: Lynnette A
authors.initials: LA
authors.lastname: Averill
authors.affiliation: Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania; VISN4 Mental Illness Research, Education, and Clinical Center at the Philadelphia VA Medical Center, Philadelphia, Pennsylvania.
authors.forename: J
authors.initials: J
authors.lastname: Cobb Scott
authors.affiliation: National Center for PTSD - Clinical Neurosciences Division, US Department of Veterans Affairs, West Haven, CT, United States; Department of Psychiatry, Yale University School of Medicine, New Haven, CT, United States.
authors.forename: Christopher L
authors.initials: CL
authors.lastname: Averill
authors.affiliation: Department of Psychiatry, University of Connecticut Medical Center, Farmington, CT, United States.
authors.forename: Brian
authors.initials: B
authors.lastname: Schweinsburg
authors.affiliation: National Center for PTSD - Clinical Neurosciences Division, US Department of Veterans Affairs, West Haven, CT, United States; Department of Psychiatry, Yale University School of Medicine, New Haven, CT, United States.
authors.forename: Marcia
authors.initials: M
authors.lastname: Trejo
authors.affiliation: National Center for PTSD - Clinical Neurosciences Division, US Department of Veterans Affairs, West Haven, CT, United States; Department of Psychiatry, Yale University School of Medicine, New Haven, CT, United States.
authors.forename: Alicia
authors.initials: A
authors.lastname: Roy
authors.affiliation: National Center for PTSD - Clinical Neurosciences Division, US Department of Veterans Affairs, West Haven, CT, United States; Department of Psychiatry, Yale University School of Medicine, New Haven, CT, United States.
authors.forename: Valerie
authors.initials: V
authors.lastname: Weisser
authors.affiliation: National Center for PTSD - Clinical Neurosciences Division, US Department of Veterans Affairs, West Haven, CT, United States; Department of Psychiatry, Yale University School of Medicine, New Haven, CT, United States.
authors.forename: Christopher
authors.initials: C
authors.lastname: Kelly
authors.affiliation: National Center for PTSD - Clinical Neurosciences Division, US Department of Veterans Affairs, West Haven, CT, United States; Department of Psychiatry, Yale University School of Medicine, New Haven, CT, United States.
authors.forename: Brenda
authors.initials: B
authors.lastname: Martini
authors.affiliation: National Center for PTSD - Clinical Neurosciences Division, US Department of Veterans Affairs, West Haven, CT, United States; Department of Psychiatry, Yale University School of Medicine, New Haven, CT, United States.
authors.forename: Ilan
authors.initials: I
authors.lastname: Harpaz-Rotem
authors.affiliation: National Center for PTSD - Clinical Neurosciences Division, US Department of Veterans Affairs, West Haven, CT, United States; Department of Psychiatry, Yale University School of Medicine, New Haven, CT, United States.
authors.forename: Steven M
authors.initials: SM
authors.lastname: Southwick
authors.affiliation: National Center for PTSD - Clinical Neurosciences Division, US Department of Veterans Affairs, West Haven, CT, United States; Department of Psychiatry, Yale University School of Medicine, New Haven, CT, United States.
authors.forename: John H
authors.initials: JH
authors.lastname: Krystal
authors.affiliation: National Center for PTSD - Clinical Neurosciences Division, US Department of Veterans Affairs, West Haven, CT, United States; Department of Psychiatry, Yale University School of Medicine, New Haven, CT, United States. Electronic address: chadi.abdallah@yale.edu.
authors.forename: Chadi G
authors.initials: CG
authors.lastname: Abdallah
mesh_terms: D000328:Adult; D002540:Cerebral Cortex / Q000000981:diagnostic imaging / Q000473:pathology*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales; D013313:Stress Disorders, Post-Traumatic / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology*; D014481:United States; D014728:Veterans; D055815:Young Adult
keywords: Combat; Cortical thickness; Neuroimaging; PTSD; Veteran