Coordinate based meta-analysis of whole-brain voxel-based morphometry studies does not show evidence of grey matter loss specific to PTSD

Abstract

Neuroimaging studies have detected structural alteration in post-traumatic stress disorder (PTSD), but findings are inconsistent. This might be explained by heterogeneity between subjects with PTSD in terms of common comorbidities such as depressive and anxiety disorders and also in traumatic experience. Despite this, coordinate based meta-analysis (CBMA) has been used to try and identify localised grey matter changes, and does suggest some PTSD specific pathology. However, there are multiple technical issues that make the meta-analytic evidence questionable, warranting a re-evaluation.\n\nA literature search for voxel-based morphometry studies was performed. Only whole-brain studies using subjects with a current diagnosis of PTSD, and having a comparison group of either healthy or trauma exposed controls, were included. Twenty one voxel-based morphometry studies met the inclusion criteria. CBMA was performed to identify altered grey matter (GM) structures.\n\nUsing a novel coordinate based random effect size meta-analysis, no grey matter structure was identified as being consistently altered in PTSD compared to controls. This was also verified using the activation likelihood estimate algorithm.\n\nThere is no evidence, from CBMA, of consistent localised grey matter changes specific to PTSD. Inconsistency may reflect true heterogeneity in PTSD pathology or methodological issues with imaging and/or analysis, limiting the detection of PTSD specific pathology.