Effects of stressful life events on human brain structure: a longitudinal voxel-based morphometry study.

Although stressful life events (SLEs) have been associated with an increased risk of illness and mental disorder, their impact on brain anatomy remains poorly understood. Using a longitudinal design, we tested the hypothesis that SLEs are significantly associated with changes in gray matter volume (GMV) in brain regions previously implicated in post-traumatic stress disorder (PTSD) in a group of clinically healthy adults. Magnetic resonance imaging was used to acquire an anatomical scan from 26 subjects (13 males and 13 females; mean age ± SD: 25.2 ± 4.3 years), with no psychiatric diagnosis, at two time points with a 3-month interval. Voxel-based morphometry was used to examine an association between SLEs and gray matter changes during this period. The number of SLEs was associated with a decrease in GMV in the anterior cingulate, hippocampus, and parahippocampal gyrus (p < 0.001). In contrast, there were no areas where the number of SLEs was associated with an increase in GMV. These results provide evidence that, in adults with no formal psychiatric diagnosis, SLEs are associated with GMV decreases in a subset of regions implicated in PTSD, and that these alterations can be observed within a period as short as 3 months.

Attachment style, affective loss and gray matter volume: a voxel-based morphometry study.

Early patterns of infant attachment have been shown to be an important influence on adult social behavior. Animal studies suggest that patterns of early attachment influence brain development, contributing to permanent alterations in neural structure; however, there are no previous studies investigating whether differences in attachment style are associated with differences in brain structure in humans. In this study, we used Magnetic Resonance Imaging (MRI) and voxel-based morphometry (VBM) to examine for the first time the association between attachment style, affective loss (for example, death of a loved one) and gray matter volume in a healthy sample of adults (n = 32). Attachment style was assessed on two dimensions (anxious and avoidant) using the ECR-Revised questionnaire. High attachment-related anxiety was associated with decreased gray matter in the anterior temporal pole and increased gray matter in the left lateral orbital gyrus. A greater number of affective losses was associated with increased gray matter volume in the cerebellum; in this region, however, the impact of affective losses was significantly moderated by the level of attachment-related avoidance. These findings indicate that differences in attachment style are associated with differences in the neural structure of regions implicated in emotion regulation. It is hypothesized that early attachment experience may contribute to structural brain differences associated with attachment style in adulthood; furthermore, these findings point to a neuronal mechanism through which attachment style may mediate individual differences in responses to affective loss.