Examining brain structures associated with perceived stress in a large sample of young adults via voxel-based morphometry.

Perceived stress reflects the extent to which situations are appraised as stressful at a given point in one's life. Past brain imaging studies have examined activation patterns underlying the stress response, yet focal differences in brain structures related to perceived stress are not well understood, especially when considering gray matter (GM) and white matter (WM) structures simultaneously. In this study, voxel-based morphometry was used to investigate relations between GM/WM volume and perceived stress levels in a large young adult sample. Participants (138 men, 166 women) completed the Perceived Stress Scale (PSS; Cohen et al., 1983) and underwent an anatomical magnetic resonance imaging scan. Higher PSS scores were associated with larger GM volume in a cluster that included regions in the bilateral parahippocampal gyrus, fusiform cortex, and entorhinal cortex and smaller GM volume in a cluster that included regions of the right insular cortex. Higher PSS scores were also related to smaller WM volume in a cluster that included the body of the corpus callosum. This pattern of results remained significant even after controlling for effects of general intelligence, socioeconomic status, and depression. Together, findings suggest a unique structural basis for individual differences in perceived stress, distributed across different GM and WM regions of the brain.