Differential effects of deployment and nondeployment mild TBI on neuropsychological outcomes

Mild traumatic brain injury (TBI) that occurs in a deployment environment is characteristically different from mild TBI that occurs outside of deployment. This study evaluated differential and interaction effects of deployment and nondeployment mild TBI on cognitive and behavioral health outcomes. Research Combat veterans (N = 293) who passed performance-validity measures completed the Mid-Atlantic MIRECC Assessment of TBI (MMA-TBI), Clinician-Administered Posttraumatic Stress Disorder (PTSD) Scale (CAPS-5), a neuropsychological assessment battery, and self-report questionnaires. A 2 × 2 × 2 analysis of variance (ANOVA) was conducted to evaluate the main and interaction effects across mild TBI groups and PTSD diagnosis. Deployment TBI was associated with poorer outcomes on several cognitive tests: Wechsler Adult Intelligence Scale, 4th edition (WAIS-IV); Working Memory Index (WMI; p = .018); Trail Making Test A (TMT-A; p < .001); and Trail Making Test B (TMT-B; p = .002). Deployment TBI and PTSD were also associated with increased PTSD, depressive, and neurobehavioral symptoms; pain interference; and poorer sleep quality. Nondeployment TBI had no effect on cognitive performance and was associated only with poorer sleep quality. PTSD had the strongest associations with symptom measures and deployment TBI with cognitive outcomes. There were no significant interaction effects after adjusting for multiple comparisons. Remote outcomes associated with mild deployment TBI are different from those associated with nondeployment mild TBI and are robust beyond PTSD. This suggests that the environment surrounding a TBI event influences cognitive and symptom sequelae. Veterans who experience mild TBI during deployment may report changes in cognition, but most will continue to function within the expected range. (PsycInfo Database Record (c) 2021 APA, all rights reserved).