Voxel-based morphometric gray matter correlates of posttraumatic stress disorder

• Voxel-morphometric correlates of PTSD varied with severity and symptom clusters.
• Greater severity predicted greater amygdala/hippocampus gray matter.
• Greater avoidance/numbing predicted greater amygdala/hippocampus gray matter.
• Greater hyper-arousal was associated with less medial PFC gray matter.
• This suggests differential structural remodeling in associated brain regions.

Posttraumatic stress disorder (PTSD) is associated with functional abnormalities within a neurocircuitry that includes the hippocampus, amygdala, and medial prefrontal cortex. Evidence of structural abnormalities within these regions, and their association with PTSD severity and symptom burden is, however, sparse. The present study evaluated the relation between indices of gray matter volume and PTSD symptom severity using voxel-based morphometry. Fifteen individuals meeting DSM-IV criteria for PTSD completed the Clinician Administered PTSD Scale and underwent structural magnetic resonance imaging. Greater PTSD severity and avoidance/numbing were correlated with increased gray matter volume of the right amygdala–hippocampal complex. Greater hyper-arousal was associated with reduced gray matter volume in the left superior medial frontal gyrus. Findings are consistent with current neurocircuitry models of PTSD, which posit that the disorder is associated with structural and functional variance within this distributed network.