Over the past few years, investigators have focused on the similarities and differences between concussions/mild traumatic brain injury and post-traumatic stress disorders.
New information suggests combat-related post-traumatic stress disorder (PTSD) symptoms appear to be associated with longer-term physical (headache, tinnitus), emotional (irritability) and cognitive (diminished concentration or memory) symptoms.
Conversely, concussion/mild traumatic brain injuries (MTBI) do not appear to have long-term negative effects on troops.
“Nearly 2 million troops have been deployed to Operation Enduring Freedom and Operation Iraqi Freedom since 2001,” the authors wrote as background information in the article.
“High levels of combat exposure have been documented among Operation Enduring Freedom/Operation Iraqi Freedom-deployed soldiers, with increased risk of blast exposure and injury and development of post-deployment mental and physical health problems.”
Although there has been a focus by the Department of Defense and the Veterans Administration on early identification of concussion, little data exist on the long-term, functional effects of concussion on returning soldiers.
To examine the associations between concussion and PTSD symptoms reported during deployment and long-term psychosocial outcomes, a team led by Melissa A. Polusny, Ph.D., of the Minneapolis Veterans Affairs Health Care System and the University of Minnesota Medical School in Minneapolis, surveyed 953 combat-deployed U.S. National Guard Soldiers.
Consistent with demographics of infantry soldiers deployed to Iraq, 92.5 percent of participants were male, 87.1 percent were white, 46.4 percent were younger than 30 and 86.5 percent were enlisted rank. Soldiers were surveyed in Iraq one month before returning home, and again one year later.
At the time of the first survey, 7.6 percent of all participating soldiers met criteria for probable PTSD. This rate increased to 18.2 percent at the time of the second survey. Change in PTSD symptoms between the two surveys was no different for those who reported concussion in the first survey and those who did not. Reporting of PTSD at the time of survey one strongly predicted post-deployment symptoms, including memory and balance problems, difficult concentrating and irritability.
The rate of reported concussion at the time of the first survey was 9.2 percent and increased to 22 percent at the second survey. Of those reporting concussion at the first survey, 30.2 percent had probable PTSD at the time of the second survey. Additionally, of the 22 percent who reported concussion during the second survey, 30.4 percent also had probable PTSD at that time.
Soldiers with a history of reported concussion were also more likely to report post-concussive symptoms after deployment; however, after adjusting for PTSD symptoms, the association between these symptoms and concussion was not significant.
“Although combat-related PTSD was strongly associated with post-concussive symptoms and psychosocial outcomes one year after soldiers return from Iraq, there was little evidence of a long-term negative impact of concussion/mild traumatic brain injury history on these outcomes after accounting for PTSD,” the authors said.
“These findings and the two-fold increase in reports of deployment-related concussion/MTBI history have important implications for screening and treatment.”
The report is found in the January issue of Archives of General Psychiatry, one of the JAMA/Archives journals.