Background: Preclinical studies have demonstrated the relationship between stress-induced increased cortisol levels and atrophy of specific brain regions, however, this association has been less revealed in clinical samples. The aim of the present study was to investigate the changes and associations of the hypothalamic-pituitary-adrenal (HPA) axis activity and gray matter volumes in young healthy adults with self-reported childhood trauma exposures.
Methods: Twenty four healthy adults with childhood trauma and 24 age- and gender-matched individuals without childhood trauma were recruited. Each participant collected salivary samples in the morning at four time points: immediately upon awakening, 30, 45, and 60 min after awakening for the assessment of cortisol awakening response (CAR). The 3D T1-weighted magnetic resonance imaging data were obtained on a Philips 3.0 Tesla scanner. Voxel-based morphometry analyses were conducted to compare the gray matter volume between two groups. Correlations of gray matter volume changes with severity of childhood trauma and CAR data were further analyzed.
Results: Adults with self-reported childhood trauma showed an enhanced CAR and decreased gray matter volume in the right middle cingulate gyrus. Moreover, a significant association was observed between salivary cortisol secretions after awaking and the right middle cingulate gyrus volume reduction in subjects with childhood trauma.
Conclusions: The present research outcomes suggest that childhood trauma is associated with hyperactivity of the HPA axis and decreased gray matter volume in the right middle cingulate gyrus, which may represent the vulnerability for developing psychosis after childhood trauma experiences. In addition, this study demonstrates that gray matter loss in the cingulate gyrus is related to increased cortisol levels.