Matt Friedman, the director of the National Center for PTSD, explained at the 2003 conference of the American Association for the Advancement of Science that the SOF soldiers in the Fort Bragg study demonstrated a higher capacity to mobilize the neuropeptide Y molecule and sustain it for longer periods of time. Furthermore, the level of neuropeptide Y their bloodstream returned to normal levels within twenty-four hours, whereas conventional soldiers still showed decreased levels.

According to Friedman, the capacity to mobilize neuropeptide Y is correlated to a lower likelihood of developing PTSD. He believes that neuropeptide Y may offer the key to primary prevention of PTSD, if a means of artificially elevating it could be discovered.  Although the work has been going on for several years, researchers are still uncertain whether the SOF members’ enhanced capacity to endure trauma was genetic or had been acquired through Special Forces training.

A broader and more focused study conducted in 2012 by researchers in the Department of Psychological Medicine in Sri Lanka[ii] compared the mental health problems of SOF personnel with conventional forces who had been engaged in combat for at least one year.  Exposure to traumatic events and problems with family life were identified as risk factors. The outcome measures were common mental disorder, fatigue, multiple physical symptoms and hazardous alcohol use.The researchers found that while overall exposure to potentially traumatic events was high in both groups, the SOF personnel experienced significantly more traumatic events during their tours than conventional forces.

In spite of this, Special Forces personnel exhibited significantly fewer common mental disorders, fatigue or poor general health than regular forces.  Prevalence of PTSD was only 1.9% in the Special Forces and 2.9% among the conventional forces.  So, even with more exposure to trauma, the SOF members still had lower rates of PTSD.  The researchers suggested that better training, comradeship, and unit cohesion protected Special Forces personnel from negative mental health outcomes of combat.