The Impact of Mild Traumatic Brain Injury Sustained with Blast or Nonblast Mechanism During Combat or Noncombat...

Community reintegration serves an integral role to enhance veterans' quality of life as they transition to civilian life. Unsuccessful reintegration after military separation may contribute to the relative increase in adverse outcomes such as homelessness and suicide in this population. Mild traumatic brain injury (TBI) has been linked to poor mental health, which, in turn, may compromise community reintegration; however, little is known about how the characteristics of mild TBI may impact community reintegration either directly or indirectly. The objectives of this study are to: (1) evaluate the association of the characteristics of mild TBI, including blast versus nonblast mechanism and combat versus noncombat deployment (i.e., outside of combat deployment) setting on community reintegration; (2) determine whether this association varies by the level of perceived social support; and (3) explore the potential mediation effect of mental health symptom levels. This cross-sectional analysis used data from the Long-term Impact of Military-relevant Brain Injury Consortium Chronic Effects of Neurotrauma Consortium (LIMBIC-CENC) Prospective Longitudinal Study on 2,177 service members and veterans (SMVs) who were registered for clinical care at a Department of Defense and/or Veterans' Affairs Medical Facility. The exposure of interest was the characteristics of each mild TBI, including from blast/nonblast mechanism, combat deployment/noncombat deployment setting, or lack of any lifetime mild TBI. The outcome was community reintegration measured by the Community Reintegration of Injured Service Members survey. Perceived social support was measured using the Deployment Risk & Resilience Inventory-2 Post-deployment Social Support Scale. Mental health symptoms (post-traumatic stress and depressive) were evaluated using the post-traumatic stress disorder checklist, DSM-5, and the Patient Health Questionnaire-9, respectively. Community reintegration among SMVs who sustained mild TBI(s) only with a nonblast mechanism outside of a combat deployment was better compared with those sustaining mild TBI(s) during a combat deployment or by blast mechanism. Those with no mild TBI history had a similar level of community reintegration as those who sustained nonblast mild TBI(s) outside of combat deployment. The level of perceived social support did not significantly alter these relationships; however, inclusion of variables to account for mental health symptoms in the models attenuated the results to nonsignificance, supporting potential mediation by mental health symptoms. This study found mild TBI sustained during combat deployment (either blast or nonblast mechanism) may be a risk factor for poor community reintegration. These results support clinical care processes that include identifying SMs with sustained mild TBI during combat deployment (particularly those with blast mechanism) for targeted interventions that may facilitate transition into the community. Future studies are needed to evaluate the mechanism through which mild TBI sustained during combat deployment for both blast and nonblast type injuries may impact community reintegration.