Gray Matter Correlates of Posttraumatic Stress Disorder: A Quantitative Meta-Analysis

Background: Since the inception of the diagnosis posttraumatic stress disorder (PTSD), attempts have been undertaken to understand why only a subpopulation of individuals exposed to trauma develops PTSD. Cerebral gray matter reductions have been suggested to be a crucial pathobiological marker of PTSD. However, a quantitative meta-analysis of whole-brain voxel-based morphometry studies is lacking. Methods: Here, we investigated concurrence across voxel-based morphometry studies in PTSD compared with trauma-exposed individuals without PTSD (all together nine studies with 319 subjects) by means of activation likelihood estimation. Results: We identified brain regions of consistent gray matter reduction in anterior cingulate cortex, ventromedial prefrontal cortex, left temporal pole/middle temporal gyrus, and left hippocampus in PTSD patients compared with individuals exposed to trauma without PTSD. Conclusions: This is the first quantitative whole-brain meta-analysis showing brain structure deficits in traumatized subjects with PTSD compared with trauma-exposed healthy control subjects. The gray matter deficit profile overlaps with brain networks of emotion processing, fear extinction, and emotion regulation known to be affected in PTSD. Although the data cannot clarify if this is a predisposition or a consequence of the disease, the results may facilitate the need to control for structural characteristics in future functional brain studies.