Gray matter differences in adults and children with posttraumatic stress disorder: A systematic review and meta-analysis of 113 studies and 11 meta-analyses

Background: In this systematic review and meta-analysis, we aimed to provide a comprehensive overview of gray matter alterations of adult-and underage patients with posttraumatic stress disorder (PTSD) in comparison to healthy trauma-exposed (TC) and non-exposed (HC) individuals. Methods: We subdivided our groups into patients with PTSD after trauma exposure in adulthood (aa) or child-hood (ac) as well as children with PTSD (cc). We identified 113 studies, including 6.800 participants in our review, which we divided into studies focusing on whole-brain and region-of-interest (ROI) analysis. We per-formed a coordinate-based meta-analysis on 14 studies in the group of aa-PTSD. Results: We and found lower gray matter volume in patients with PTSD (aa) in the medial frontal gyrus (PTSD<HC/TC) and Culmen/posterior cingulate cortex (PTSD<TC). Results from ROI-based studies mainly show alterations for patients with PTSD in the prefrontal cortex, hippocampus, anterior cingulate cortex, insula, corpus callosum, and amygdala. Limitations: Due to a limited number of studies reporting whole-brain results, the meta-analyses could only be performed in one subgroup and within this subgroup for a limited number of studies. Conclusions: Our results are in line with psychobiological models of PTSD that associate the identified regions with brain circuits involved in context processing, threat detection and emotion regulation.