Chronic stress conditions do explain posttraumatic brain injury depression.

Psychosocial and biologic mechanisms are implicated in depression after traumatic brain injury (TBI). Using McEwen's stress theory of allostasis as a guidepost, this study examined whether pre- and postinjury chronic stress conditions could explain post-TBI depressive symptoms. Seventy-five community-dwelling persons who sustained a mild-to-moderate TBI and were within 2 years of the injury participated in this cross-sectional study. The participants completed measures of chronic stress and depression, measured with the Neurobehavioral Functioning Inventory. Data were collected also on brain injury severity. Using multiple regression analysis, the frequency of childhood adversities and postinjury stress explained post-TBI depression. When time-since-injury was in the regression model, the frequency of preinjury stressors and postinjury stress significantly explained post-TBI depressive symptoms while the combined effect of childhood adversity with postinjury stress was not significant in explaining depressive symptoms. Pre- and postinjury chronic stress explained post-TBI depressive symptoms. These findings support stress-diathesis theory within the psychiatric literature and a linkage between chronic stress, an indicator of allostatic load, and post-TBI depression. These findings are important for nurse specialists working with persons who sustained brain injury, for chronic stress can be buffered by efficient and effective support systems.