By examining blood samples drawn from U.S. marines who have served in combat zones, a team of researchers has identified genetic markers that are linked with post-traumatic stress disorder (PTSD).
For their study published in the journal Molecular Psychiatry on March 10, Dewleen Baker from the University of California, San Diego and colleagues analyzed the blood samples of 188 marines from the U.S. The samples were taken prior to and after the deployment of the marines to conflict zones.
PTSD is a mental condition that can happen after a person experiences a terrifying event or situation with violent assaults, such as those seen during military combat, natural and man-made disasters and accidents, all of which are known to be common triggers of the condition.
The researchers were able to identify biomarkers that are associated with innate immune response, which provide the body with the initial defense against pathogens as well as with interferon signaling linked with PTSD.
Baker said that they were able to identify the genetic markers of interferon signaling and innate immunity before and after the development of PTSD. The results of the experiment were likewise replicated in a second analysis involving another group of marines.
"The question to ask is what's stimulating an interferon response prior to PTSD development," Baker said. "The answer could be any number of factors, ranging from a simple explanation of increased anticipatory stress prior to deployment or more complex scenarios where individuals may have a higher viral load."
The researchers said that the findings could lead to new ways of improving the diagnosis and treatment of individuals with PTSD and make predictions as to who might be susceptible to the condition. The interferon signaling networks, for instance, may serve as a molecular signature that can predict increased risks for PTSD.
"These findings provide novel insights for early preventative measures and advanced PTSD detection, which may lead to interventions that delay or perhaps abrogate the development of PTSD," the researchers wrote.
Experts said that what sets PTSD apart and makes it more challenging to study compared with other psychiatric orders is that it involves a traumatic experience that serves as a trigger. The researchers said that their study did not only allow them to identify the differences between the participants with PTSD and those without. In essence, it also allowed them to travel back in time to determine if any of those who developed PTSD have biomarkers that suggest they would likely develop the condition.
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