King's College London

Objective: The authors conducted a comprehensive metaanalysis
of MRI region-of-interest and voxel-based morphometry
(VBM) studies in posttraumatic stress disorder
(PTSD). Because patients have high rates of comorbid depression,
an additional objective was to compare the findings
to a meta-analysis of MRI studies in depression.

Method: The MEDLINE database was searched for studies
from 1985 through 2016. A total of 113 studies met inclusion
criteria and were included in an online database. Of these,
66 were selected for the region-of-interest meta-analysis
and 13 for the VBM meta-analysis. The region-of-interest
meta-analysis was conducted and compared with a metaanalysis
of major depressive disorder. Within the regionof-interestmeta-analysis,
three subanalyses were conducted that included control groups with and without trauma.

Results: In the region-of-interest meta-analysis, patients with
PTSD compared with all control subjects were found to
have reduced brain volume, intracranial volume, and volumes
of the hippocampus, insula, and anterior cingulate. PTSD
patients compared with nontraumatized or traumatized control
subjects showed similar changes. Traumatized compared
with nontraumatized control subjects showed smaller
volumes of the hippocampus bilaterally. For all regions, pooled
effect sizes (Hedges’ g) varied from 20.84 to 0.43, and
number of studies from three to 41. The VBM meta-analysis
revealed prominent volumetric reductions in the medial
prefrontal cortex, including the anterior cingulate. Compared
with region-of-interest data from patients with major depressive
disorder, those with PTSD had reduced total brain
volume, and both disorders were associated with reduced
hippocampal volume.

Conclusions: The meta-analyses revealed structural brain
abnormalities associated with PTSD and trauma and suggest
that global brain volume reductions distinguish PTSD
from major depression.