Brain morphometry changes and depressive symptoms after traumatic brain injury

Traumatic brain injury (TBI) is associated with an increased risk of depressive symptoms. Recent imaging studies on spontaneous depression have implicated several brain structures; however, few studies have done the same for post-TBI depression. We report on a pilot observational study correlating atrophy of brain regions of interest in subjects after TBI with depressive symptoms measured by the Beck Depression Inventory-II. Regional brain volumes were calculated on both acute and 6-month MRI using an automated segmentation algorithm (FreeSurfer). Percent volume changes in brain regions were correlated with BDI-II scores using Spearman's rank order correlation coefficient. Correction for multiple comparisons was performed using the false discovery rate (FDR). Three regions of interest (left rostral anterior cingulate and bilateral orbitofrontal cortex) were found to be significantly correlated with depressive symptoms (FDR 0.05). With FDR 0.1, six regions were significantly correlated. The use of volumetric analysis of brain regions of interest to study post-TBI depression is worthy of further study. Regions associated with depressive symptoms in this pilot study were similar to those implicated in study of spontaneous depression.