Risk factors for depressive symptoms after mild-to-moderate traumatic brain injury

Primary objective: To determine the extent to which pre-injury psychosocial factors, injury-related variables and post-injury litigation, perceived stress, fatigue, pain and information processing speed contributed to depressive symptoms after traumatic brain injury (TBI). Research design: Cross-sectional outpatient follow-up at 1-36 months post-injury. Methods and procedures: Eighty-four adults recruited from outpatient clinics completed measures of depressive symptoms, measured with the Neurobehavioural Functioning Inventory, chronic stress and other symptoms. Hierarchial linear regression analysis was used to identify statistically significant covariates. Logistic regression analysis determined classification accuracy of these variables with regard to the presence or absence of borderline depression levels. Main outcomes: Perceived stress, pain and litigation status made independent contributions to the level of depressive symptoms, with perceived stress explaining the bulk of the variance and mediating the effect of milder injury severity. These variables had a classification accuracy of 77% with regard to post-injury depressive symptoms, with a sensitivity of 84% and a specificity of 69%. Conclusions: Perceived stress, one indicator of allostatic load, explains a considerable amount of the variance in depressive symptoms after mild-moderate TBI. The findings suggest a need for earlier identification of, as well as preventative education with, those who are stress-vulnerable.