Mild Traumatic Brain Injury in U.S. Soldiers Returning from Iraq


This study assesses the prevalence and significance of a self-reported history of combat-related mild traumatic brain injury, based on the accepted case definition, among US soldiers after a year long deployment to Iraq. The purpose is to provide information to advance prevention and treatment strategies and inform public health policies.


Background: An important medical concern of the Iraq war is the potential long-term effect of mild traumatic brain injury, or concussion, particularly from blast explosions. However, the epidemiology of combat-related mild traumatic brain injury is poorly understood. Methods: We surveyed 2525 U.S. Army infantry soldiers 3 to 4 months after their return from a year-long deployment to Iraq. Validated clinical instruments were used to compare soldiers reporting mild traumatic brain injury, defined as an injury with loss of consciousness or altered mental status (e.g., dazed or confused), with soldiers who reported other injuries. Results: Of 2525 soldiers, 124 (4.9%) reported injuries with loss of consciousness, 260 (10.3%) reported injuries with altered mental status, and 435 (17.2%) reported other injuries during deployment. Of those reporting loss of consciousness, 43.9% met criteria for post-traumatic stress disorder (PTSD), as compared with 27.3% of those reporting altered mental status, 16.2% with other injuries, and 9.1% with no injury. Soldiers with mild traumatic brain injury, primarily those who had loss of consciousness, were significantly more likely to report poor general health, missed workdays, medical visits, and a high number of somatic and postconcussive symptoms than were soldiers with other injuries. However, after adjustment for PTSD and depression, mild traumatic brain injury was no longer significantly associated with these physical health outcomes or symptoms, except for headache. Conclusions: Mild traumatic brain injury (i.e., concussion) occurring among soldiers deployed in Iraq is strongly associated with PTSD and physical health problems 3 to 4 months after the soldiers return home. PTSD and depression are important mediators of the relationship between mild traumatic brain injury and physical health problems.

Full Reference

Hoge, C. W., McGurk, D., Thomas, J. L., Cox, A. L., Engel, C. C. and Castro, C. A. Mild Traumatic Brain Injury in U.S. Soldiers Returning from Iraq. The New England Journal of Medicine, 2008; 358:453-463. doi 10.1056/NEJMoa072972