A new study found U.S. Marines that suffered traumatic brain injuries (TBI) while deployed were at a higher risk of suffering from post-traumatic stress disorder (PTSD).
The research team concluded TBIs suffered during deployment in Iraq or Afghanistan were the "greatest predictor" of PTSD symptoms down the road, a University of California- San Diego news release reported.
PTSD is a condition triggered by stress reactions; it can include symptoms such as "depression, suicidal tendencies, substance abuse, memory and cognition dysfunction and other health problems," the news release reported.
The researchers analyzed data on 1,648 active-duty Marines and Navy servicemen and Navy servicemen. The participants had been evaluated about one week month before a seven-month deployment; they were also evaluated one week, three months, and six months after they had returned.
The servicemen were evaluated for PTSD as well as interviewed about past head injuries, especially those that occurred while the participants were deployed.
TBIs are annually sustained by about t 1.7 million Americans, and about five million are currently living with disabilities as a result.
Over half of the servicemen that participated in the study had sustained a TBI before deployment; about a fifth received one during their time in Iraq or Afghanistan. About 87 percent of the TBIs were considered to be mild; Out of the 117 study subjects that were knocked unconscious as a result of their head injury 111 were only out for 30 minutes or less.
The team found a mild TBI raised the predicted CAP scores ( a structured interview widely employed to diagnose PTSD and severity) by 1.23., a moderate or severe TBIs raised the predicted CAP scores by a factor of 1.71.
"The severity of post-deployment PTSD symptoms depends, in part, on the severity of pre-existing symptoms from prior trauma and combat intensity," principal investigator Dewleen G. Baker, MD, research director at the VA Center of Excellence for Stress and Mental Health, said. "An individual with no pre-existing PTSD symptoms and low combat intensity is at minimal risk for developing PTSD - less than a [one] percent probability. Increases in pre-existing symptom scores and combat intensity modestly increase post-deployment symptom scores by [one] to [two] percent."
"By contrast, deployment-related mild TBI increases post-deployment symptom scores by 23 percent, and moderate to severe injuries increase scores by 71 percent. This percent increase is equivalent to a 14-point increase in combat intensity scores for mild TBI, and a 37-point increase for moderate or severe TBI," Baker said.
Baker said there are other factors that can contribute to PTSD risk.
"However, TBI was the strongest predictor of PTSD, even when controlling for pre-existing symptoms and combat intensity," she said. "These findings may be used to identify individuals who may be at risk for developing PTSD and provide them with more immediate health care."
