Commentary: A biomarker for PTSD risk?
The story of PTSD is still being written. Sadly, traumatic experiences continue to be intrinsic to human life, even outside the context of war. The continued presence of the U.S. armed services in Afghanistan and Iraq has broadened the sense of urgency about the disorder. Up to 13% of soldiers develop it, while the lifetime prevalence of PTSD in the United States is under 8%.
Since in wartime the experience of trauma is relatively easy to detect, much research has focused on preventing the illness from developing after a trauma occurs. Studies have shown what doesn't work — so-called "debriefing" interventions are not effective and can make matters worse. In fact, as of yet, there is no treatment known to prevent PTSD. So researchers are working to identify risk factors that might predict who is most vulnerable to developing symptoms.
Some risk factors are determined by category. That is, epidemiologists can identify a group of individuals who, for example, by description (age, ethnic background) or by past psychiatric history, are more prone to developing PTSD. But such descriptors tend to be overly broad. A more useful tool, if one could find it, would be a specific biological marker. To date, investigators have studied processes, such as changes in stress hormones or immune function, that could be biomarkers, but none has identified PTSD risk in advance.