Context Matters: Influence of Injury Context on Long-Term Psychiatric and Cognitive Outcomes in Combat Veterans With Mild Traumatic Brain Injury History

Objective: To examine the relationship between injury context with psychiatric and cognitive outcomes among combat-exposed Veterans and Service Members with remote mild traumatic brain injury (mTBI). Setting: Veterans and Service Members enrolled in the Long-Term Impact of Military-Relevant Injury Consortium (LIMBIC)-Chronic Effects of Neurotrauma Consortium (CENC). Participants: LIMBIC-CENC-enrolled participants who had sustained an mTBI exclusively in combat zones (c-mTBI +; n = 314), mTBI sustained exclusively in non-combat settings (c-mTBI-; n = 526), or no history of mTBI (no TBI; n = 347). Inclusion criteria for this study included (1) availability of all mTBI injury-related characteristics, (2) completion of all psychiatric symptom measures, and (3) completion of all neuropsychological measures used for this study. Design: Cross-sectional secondary analysis. Main Measures: Primary outcomes of interest included total scores on self-reported psychiatric symptom measures (post-traumatic stress, neurobehavioral, and cognitive concerns) and objective cognitive composite test scores (attention, learning, processing speed, executive function, and delayed recall). All analyses adjusted for age, gender, and education. Results: Results of separate multivariate analyses of variance indicated that the c-mTBI+ group reported higher post-traumatic ( η P 2 = .08) and neurobehavioral symptoms ( η P 2 = .07), and cognitive concerns ( η P 2 = .04) compared to the c-mTBI- and no TBI groups, whereas the c-mTBI- and no TBI groups did not differ except on cognitive concerns. Additionally, groups did not differ across cognitive composite performance except for significant though weak group differences on learning ( η P 2 = .01), delayed recall ( η P 2 = .03), and processing speed ( η P 2 = .01). Separate hierarchical regression analyses indicated psychiatric symptom burden explained 7–18% of the total variance in cognitive composite performance as a function of mTBI group history ( p s ≤ .002). Conclusions: These findings build upon prior work showing that injury context – the context in which mTBI occurs – may play an important role in long-term psychiatric and cognitive outcomes.