Mental, Physical, and Social Mediators of the Relationship Between Mild Traumatic Brain Injury and Functional Impairment in U.S. Military Veterans

ObjectiveThis study examined mental, physical, and social variables that may mediate the relationship between mild traumatic brain injury (mTBI) and functional impairment in a nationally representative sample of U.S. military veterans. Method: Data were analyzed from 3,985 U.S. military veterans who participated in the National Health and Resilience in Veterans Study. Results: Study results revealed that 10.0% (95% confidence interval = 8.7-11.4%) of veterans screened positive for mTBI on the Veterans Affairs' Mild TBI Injury Screening and Evaluation tool. Veterans with a positive mTBI screen scored lower on measures of mental, physical, and cognitive functioning, and higher on a measure of psychosocial difficulties compared to those with a negative mTBI screen. Symptoms of major depression, generalized anxiety, and posttraumatic stress disorder, insomnia, somatic symptoms, and loneliness significantly mediated the relationship between mTBI screening status and various functional outcomes. Specifically, these mediators accounted for 87.1% of the association with physical functioning, 84.2% of the association with mental functioning, and 73.0% of the association with cognitive functioning, with mTBI screening status remaining significantly associated with each measure. For psychosocial functioning, these mediators accounted for 89.2% of the association, and mTBI screening status was no longer associated with this outcome. Conclusions: Collectively, these findings underscore the importance of early, targeted, and multi-modal interventions that address psychiatric symptoms, somatic symptoms, insomnia, and loneliness to enhance overall functioning and well-being among veterans with mTBI.