PTSD Research at Fort Bragg: Prediction and Prevention
Charles A. (Andy) Morgan III, M.D., is Director of the Stress and Resilience Laboratory within the Clinical Neurosciences Division in West Haven, CT. He and his staff have been engaged for a number of years in groundbreaking research with active-duty military personnel at the John F. Kennedy Special Warfare Center and School at Fort Bragg, NC. They are studying trainees under stress in an effort to better understand the development of PTSD. His work may point the way not only to more effective treatments but also to possible preventive measures. Janet Bailey interviewed Dr. Morgan about his work in August 2002.
How did you get involved in PTSD research with active-duty military personnel?
When I first joined the National Center for PTSD in 1989, we were working with combat veterans of the Vietnam War and later with veterans of the Gulf War. The data that were coming out of the early biological and psychological studies suggested that people with PTSD exhibited a number of differences compared to people without PTSD. There were differences in their physiology—for instance, in their startle response (how jumpy they were) to sounds when we showed them reminders of war stress. We also noted differences in certain kinds of mental symptoms such as dissociation—for instance, colors appearing brighter or events seeming to move in slow motion. And we found differences in levels of certain chemicals that are known to play a critical role in how the brain responds to stress.
What concerned me at the time was that the majority of our research was based on retrospective data. We were assessing PTSD patients in the present and making assumptions about what had happened in the past, which was sometimes decades ago. We really didn’t know whether the differences in biology, physiology, and psychology that we documented were the result of having PTSD or whether those differences in fact predated the traumatic exposure. If the latter were true, then perhaps these differences are actually risk factors that make some people more or less susceptible to developing the illness.
For instance, one might wonder why PTSD patients have differences in startle response. Well, it may be that some people have an exaggerated startle response to begin with, and those people have a heightened sensitivity to stimuli resulting in the situation where trauma has a more severe impact on them. If that’s true, then this might be something you can measure ahead of time to identify groups at higher risk for developing PTSD.
So you wanted to study people before they experienced trauma.
That’s right. I decided I wanted to do prospective, not retrospective, studies…, but it would be just about impossible to do that with PTSD research. We would have to start with a group of healthy people, hope that they get traumatized equally, assess them within the same time frame, and then follow them over time to see who gets PTSD. This certainly wasn’t going to work! So I thought, “What organization routinely puts healthy people in harm’s way?” The military.
I started contacting military bases around the country and eventually got a call from Col. Gary Greenfeld, who was the Psychological Applications Director at Fort Bragg. He had been an enlisted soldier in Vietnam, then got a psychology degree from Johns Hopkins, and later got back into the military to develop a program for Special Forces teams. He asked, “Do you think there is a profile of people who are stress-hardy versus stress-vulnerable? We want the best people we can have, and if there’s a way to identify people who might not do well under stress, we’d like to know that.” So it seemed that he and I wanted to study the two sides of the same coin.
The Military Survival School at Fort Bragg provides training in how to survive in the desert or avoid captivity and, if captured, how to avoid being exploited by the enemy. It’s a very rigorous program that includes both classroom training and exposure to a mock POW camp where trainees, after being captured, are held for a few days.
But is this really the same as experiencing stress in the real world?
Surprisingly, yes, it is. We measured trainees’ psychological symptoms before and after the training as well as physical symptoms like hormone levels and heart rate. We found that trainees report extremely high levels of dissociative responses—even higher than in people under the influence of hallucinogenic drugs. We also found that elevations in the stress hormone cortisol and reductions in testosterone were some of the most dramatic we have ever seen. After only eight hours, for instance, testosterone levels of the men were lower than levels we see in many women.
What else have you found with your research?
One of the most significant findings was with a peptide called “Neuropeptide Y.” It is a substance that, in addition to many other actions, works on the prefrontal cortex of the brain and helps you stay focused on a task even under stress. We found that the Special Forces trainees—the Green Berets—produced significantly more NPY than the Rangers and Marines who were going through the same training. Twenty-four hours after completing the training, the Green Beret trainees were back to baseline levels of NPY while the others were significantly depleted. In fact, there was a direct positive relationship between the amount of NPY and performance in the training. There also was a clear, negative relationship between performance scores and the number of dissociative symptoms reported by the trainees and [a negative relationship] between NPY and dissociation. In other words, the less NPY soldiers had, the more they dissociated, and the more they dissociated, the worse they did in their training.
We were very excited by these results! They suggest that at least some of the physiological factors predate the development of PTSD, that people who release high levels of NPY under stress stay mentally focused. They don’t have as many symptoms of dissociation, and at the end they bounce right back to where they started. Others, those that produce less NPY, performed very poorly in the training and looked a lot more anxious and frazzled at the end.
Then we looked at their trauma histories to see whether a history of childhood trauma or child abuse predicted differences when they went through training. Interestingly, those in the Green Beret units tended to have endured more child abuse but did better under stress. Trainees from the Rangers and Marines with a history of child abuse had more trouble during training. They didn’t produce as much NPY, they dissociated a lot, and they didn’t perform as well.
This of course raises a key question: Did the Green Beret trainees come that way, or was there something in their previous training in the military that helped them perform better under stress? We’re going to be looking into this question by studying the selection program this fall. By measuring NPY and other factors, will we be able to predict who the Army is going to select for the Green Beret training?
What are the implications of all this for veterans and others who suffer from PTSD? Do you see your work leading to better treatments?
We’ve been able to replicate our findings about NPY and psychological responses to stress at two Navy sites in both women and men and in the Combat Dive School in Key West. We can now argue convincingly that NPY, or drugs that work like NPY, act as anti-anxiety or anti-stress agents. At this point, we need to figure out how to develop these agents so we can use them with people who suffer from PTSD. There may come a time when replenishing NPY is a normal procedure when a person comes back from a stressful situation, in the same way that you would feed him if he had been malnourished.
Of course, the real benefit would be in prevention. For instance, a low level of NPY may be a marker that helps us identify which people may be more vulnerable to developing PTSD. We could put people on a treadmill for 20 minutes and measure their levels of NPY, along with other things. It would be like an insurance company doing statistical analysis to determine who is a good risk.
We’ve also developed a little paper-and-pencil test called an “experiences questionnaire,” which asks mostly about dissociative symptoms. Over the years, we have administered it to over 2,000 people before they began the Military Survival School, and we consistently find that people who score high on the test don’t make it through the training. If you just screened those people out at the beginning, it would save the Army millions of dollars.
Have your findings changed the selection of or methods for dealing with active-duty personnel?
One of our goals certainly is to develop cost effective methods of weeding out people who shouldn’t be there and selecting the ones that should. But the Army doesn’t like the idea that someone might be prevented from doing something he or she really wants to do. Also, the military has historically been reluctant to give too much attention to psychological problems, so there has been some institutional resistance.
Why is that?
As far back as World War I, studies of what was then called “shell shock” have shown that if people are given a way out of a difficult situation, they will take it. The British sent their soldiers back to England for treatment, and the soldiers almost never came back to the front. The French decided they couldn’t afford that, so they treated their people right at the front lines, and they had a much better rate of success.
Many people will keep working as long as they think there is nothing wrong with them—that is, as long as they don’t identify themselves as ill. The military trains their medics to identify symptoms and to recognize when to send people for some downtime. But the medics have to be careful that they don’t send the message to a person that he not only feels bad but also is useless, because then it can destroy that person’s sense of confidence. We doctors can sometimes communicate a picture that makes a person feel weak and vulnerable if we’re too quick to diagnose an illness.
Interestingly, the people who go through Special Forces training all say, at the end, that it was the best training experience of their lives. The people who don’t do so well are the individuals who leave without completing the training. They carry away a sense of failure. They think, “Not only was I scared, but I failed too.” You know, one of the best predictors of PTSD is the subjective view the person has of the traumatic experience, the story he carries around in his head, and his sense of self-efficacy.
When I’m on the military post or Navy base, I meet soldiers and sailors who have seen and done incredibly stressful things and who are, psychologically, amazingly healthy in spite of it. They go home from work just like the rest of us, they have great families, and they love their jobs. They say, “I jump out of airplanes, and it’s the greatest job in the world.” Those of us who work with patients in a clinical setting sometimes forget that most people who are exposed to trauma or stress won’t have a problem. They may have thoughts and reactions, but they won’t develop a mental disorder.
What’s next in your research?
Our research with the Military Survival School trainees is longitudinal; we’re hoping to follow these individuals over time and to find out who shows symptoms later in life. We also want to continue to study healthy people under conditions of stress. Some of my colleagues have a hard time accepting the idea that we should be studying a disorder before people have actually contracted it. But, this is the best way to understand what may be helpful in primary or secondary prevention, how to treat healthy people before they become unhealthy.
We are also using the Survival School as a venue for studying how accurate eyewitness accounts are of highly stressful events. Studies have shown that people who have PTSD sometimes change their report of events over time. They aren’t lying, but their memories change. We’ve studied people after interrogation and have found that the higher stress the interrogation, the worse the subjects’ ability to recognize their interrogators. We think this data will help us better understand the memory problems noted in people with PTSD.
I’m also trying to establish a biological studies site at Fort Bragg. With a permanent site, we could do ongoing work, studying healthy people during high stress events and following them over time. Military installations like Fort Bragg and other bases allow researchers to control for the trauma people are experiencing, which gives us an excellent model for studying stress and its effects. I think this is the best way for us to learn about preventing PTSD and developing better treatments.
