Lifetime PTSD and geriatric depression symptomatology relate to altered dorsomedial frontal and amygdala morphometry

Abstract

Posttraumatic stress disorder (PTSD) affects a large portion of combat deployed Veterans. Moreover, many individuals also suffer from comorbid late life depression (geriatric depression; GD). While a great deal of research has begun to characterize the morphometric features of PTSD and depression individually, few studies have investigated the interacting effect of these two disorders, specifically in a Veteran population. The current study used cortical and subcortical surface-based morphometry (SBM) in combination with psychological assessments of PTSD and GD symptom severity to examine morphometric alterations in Vietnam War Veterans. Our results indicated that increased GD severity, PTSD symptomatology, and their interaction, was related to decreased grey matter volume (GMV) in the left dorsomedial prefrontal cortex (dmPFC). Furthermore, increased symptomatology in the PTSD subscales of reexperiencing and hyperarousal were additionally found to be related to decreased GMV in this same dmPFC region. Subcortically, the interacting effect between PTSD and GD was also significantly related to regional shape variation in the left amygdala. These results suggest that morphometry of cortical (dmPFC) and non-neocortical regions (amygdala) putatively underlying emotional reactivity and the emotional components of memory is altered in PTSD and GD.

Keywords: Amygdala; Depression; Emotion; Hippocampus; MRI; PTSD.