Posttraumatic stress disorder (PTSD) is associated with reduced volume in the total brain and in the hippocampus, anterior cingulate, and insula, according to a study published in the American Journal of Psychiatry. This effect distinguishes PTSD from depression, in which only the volume of the hippocampus is normally affected.
This study included 89 structural MRI studies conducted between 1985 and 2016, 66 of which were used for meta-analysis of the region of interest and 13 of which were used for the meta-analysis of voxel-based morphometry.
Studies were located and selected using the MEDLINE database, with 113 studies meeting criteria for inclusion. Meta-analyses of regions of interest were compared with similar meta-analyses of major depressive disorder, and 3 subanalyses were performed to assess traumatized and nontraumatized control groups.
Individuals with PTSD showed diminished intracranial volume, total brain volume, hippocampal volume, insular volume, and anterior cingulate volume compared with the control group. Individuals with PTSD showed similar results when compared with both traumatized and nontraumatized patients, though traumatized patients generally showed smaller hippocampal volumes than nontraumatized controls. The number of studies for each region ranged from 3 to 41 and pooled effects sizes (Hedges’ g) ranged between -0.84 and 0.43. Significant decreases in medial prefrontal cortical volume were observed via voxel-based morphometry. Compared with major depressive disorder, brain volume was reduced in PTSD.
Researchers conclude that “[the] meta-analyses revealed structural brain abnormalities associated with PTSD and trauma and suggest that global brain volume reductions distinguish PTSD from major depression.”
Bromis K, Calem M, Reinders AATS, Williams SCR, Kempton MJ. Meta-analysis of 89 structural MRI studies in posttraumatic stress disorder and comparison with major depressive disorder [published online July 19, 2018]. Am J Psychiatry. doi: 10.1176/appi.ajp.2018.17111199