Concussion/mTBI During Deployment Does Not Result in Significant Post-Deployment Health Effects Separate from PTSD
BACKGROUND:
Troops deployed to Iraq and Afghanistan are at high risk for exposure to combat events resulting in mild traumatic brain injury (mTBI), or concussion, and PTSD. The prevalence of PTSD among military personnel deployed to OEF/OIF generally ranges between 10% and 17%, and rates are higher among Veterans receiving VA healthcare. The long-term impact of combat-related concussion/mTBI and comorbid PTSD on the health and well-being of troops is unknown. This study assessed the longitudinal associations between concussion/mTBI and PTSD symptoms reported in-theater and longer-term psychosocial outcomes in combat-deployed National Guard soldiers (n=953). Soldiers were surveyed in Iraq one month before returning home from an extended 16-month combat deployment (Time 1), and again one year later (Time 2). Investigators compared soldiers on a range of psychosocial outcomes (post-concussive, depression, and physical symptoms; alcohol use; social functioning; and quality of life) one year after returning home.
FINDINGS:
- The rate of self-reported concussion/mTBI was 9% at Time 1 and 22% at Time 2. Differences may be explained by recall bias and/or poor reliability of the TBI screening instrument.
- Prevalence of probable PTSD at Times 1 and 2 were 8% and 14%, respectively; and for probable depression were 9% and 18%, respectively. At Time 2, 42% screened for problematic drinking and 29% endorsed clinically-significant non-specific somatic complaints.
- Self-reported post-concussive symptoms at Time 2 were common. For example, among those who reported neither mTBI nor PTSD, 23% reported balance problems, 57% reported tinnitus, 60% reported memory problems, and 64% reported concentration problems and irritability. Post-concussive symptom prevalences were even higher among those who reported mTBI and/or PTSD.
- The increased post-concussive symptoms reported by soldiers reporting concussion/mTBI were no longer statistically significant after adjusting for post-deployment PTSD symptoms, suggesting that post-concussion symptoms may be largely explained by PTSD.
- Findings suggest that early identification and evidence-based treatment of PTSD may be important to the management of post-concussive symptoms following deployment.
LIMITATIONS:
- This study did not quantify exposure to concussion/mTBI events during deployment and could not address whether repeated concussion/mTBI may be associated with poorer post-deployment outcomes than single concussions.
- This study did not address the impact of moderate to severe TBI, which is clinically distinct from concussion/m/TBI.
AUTHOR/FUNDING INFORMATION:
This study was partly supported by HSR&D (RRP 08-252). Drs. Polusny and Kehle are part of HSR&D’s Center for Chronic Disease Outcomes Research, Minneapolis.
Polusny M, Kehle S, Nelson N, et al. Longitudinal Effects of Mild TBI and PTSD Comorbidity on Post-Deployment Outcomes in National Guard Soldiers Deployed to Iraq. Archives of General Psychiatry. January 2011;68(1):79-89.
