Minnesota psychologist grapple with the challenges of post-traumatic stress
An explosive flashback to combat jolts a veteran into a defensive crouch as he watches the TV news. A woman raped decades ago shakes uncontrollably as she walks along a dark street. A tsunami survivor awakens screaming from a recurring nightmare of a child swept away. >>> Trauma can leave scars that last a lifetime. Long after the danger has passed, a condition known as post-traumatic stress disorder (PTSD) keeps dragging us back to relive it.
PTSD occurs when memories of trauma become tormenting and disruptive, even disabling. Time and again, the trauma rears up in thoughts, dreams, or flashbacks. PTSD sufferers may lash out, become depressed or irritable, experience intense anxiety or panic, have difficulty concentrating or sleeping, and even become suicidal.
Several University of Minnesota psychologists are exploring this condition in work that ranges from the study of brain mechanisms to clinical counseling. How does the brain respond to traumatic events? What makes these psychological wounds so indelible? Why do some people succumb while others seem unharmed? And how can PTSD be treated? Research now under way promises some answers to such questions for people traumatized by war, sexual assault, natural disasters, accidents, terrorist attacks, or the death of a loved one.
On the front lines
According to the National Comorbidity Survey, 5 percent of men and 10 percent of women in the general U.S. population suffer from PTSD at some point in their lives. But few people see the faces of PTSD as intimately as does Brian Engdahl (Left).
Engdahl (B.A. '75, Ph.D. '80, psychology), a clinical associate professor in the department, works as a rehabilitation psychologist at the Veterans Affairs Medical Center in Minneapolis, where the trauma of war reverberates for decades after the shooting stops. His patients include octogenarian World War II POWs who still deal with intrusive memories of combat, executions of fellow POWs, or the removal of dead children from the rubble of bombed-out buildings. And they include young soldiers freshly returned from Iraq, some so wary of crowds that they can't go to the grocery store.
"When we are threatened with death, our bodies, by virtue of evolution, turn on every system they possibly can," says Engdahl. "Some of those systems may not fully reset in the original position. A one-time life-threatening situation can change you for the rest of your life."
The war in Iraq has recently brought PTSD back into the spotlight. According a 2004 study published in the New England Journal of Medicine, about 16 percent of military personnel returning from Iraq suffer from PTSD, depression, or anxiety -- a rate that may climb because onset of the disorder is sometimes delayed. PTSD even strikes people far from the front lines with surprising frequency.
Our evolving understanding of this terrible affliction has run parallel to Engdahl's career. Engdahl began working at the V.A. hospital as an intern in the 1970s, in what he calls "the bad old days." The medical establishment believed then that adult exposure to trauma would not lead to long-lasting problems in the absence of preexisting issues such childhood abuse. Vets complaining of nightmares and flashbacks were told, "You're just going to have to learn to live with it. You have your arms and legs; go back home."
Veterans of Vietnam, however, changed all that. In 1980, the American Psychiatric Association finally added PTSD to the Diagnostic and Statistical Manual of Mental Disorders III, declaring that PTSD was a bona fide illness with clinical symptoms.
"When you're able to lay out a list of common problems and signs of psychological injury, it's a great relief -- I'm not alone, it wasn't just me," says Engdahl. "It was quite an eye opener for vets, because their tendency had been to go home and suffer in silence and think they were the only one, that they were weak."
Memories run amokMany researchers believe the severe traumas of modern life trigger the same processes that evolved to help our ancestors respond to events like attacks by wild beasts. Research has shown that PTSD may be associated with alterations in the central and autonomic nervous systems. "It's a disregulation of the system's inhibitory mechanisms," says professor Bruce Cuthbert (Right), who researches mood and anxiety disorders. "Because they've been overstressed, they've gotten out of whack."
People tend to remember things that are the most arousing -- a useful evolutionary adaptation, notes Cuthbert, because "it's more practical to remember the tiger at the waterhole than the little innocent bird." But a traumatic experience may be so stimulating that it overloads and resets these systems. One hypothesis asserts that trauma causes an imbalance of hormones acting on the hippocampus, the part of the brain involved in the consolidation of memory.
"You wind up with this maladaptive storage of the memory," explains Cuthbert. "It's so strong that it overwhelms the memory system -- and that's why you get the flashbacks and the nightmares."
Intrusive memories are a defining symptom of PTSD. Memories spill out in a chaos of images; for one patient, for example, the sight of a child at a playground conjures vivid memories of the crash that killed her own child. Yet this process remains only partially understood.
Cuthbert's research seeks to develop new models and measures to understand mood and anxiety disorders and their relationship to the major motivational systems of the brain. In one study published in Psychophysiology in 2003, Cuthbert and a group of colleagues (including Christopher Patrick) measured the physiological response to fear imagery in people with PTSD and other anxiety disorders.
While subjects were exposed to fear-triggering images, researchers measured heart rate, electrical activity in the skin, and the eye blink reflex known as "potentiated startle response." Surprisingly, they found that the physiological response of people with PTSD was weaker than in people with social anxiety or snake phobias. This was puzzling, because PTSD patients tended to report more symptoms like anxiety and depression.
Cuthbert hypothesizes that PTSD is not simply a matter of hyperarousal. Indeed, clinical counselors have long observed a sometimes contradictory range of symptoms among people with PTSD: some are so edgy that they dive for cover at the sound of a car backfire while others are unresponsive and emotionally numbed.
"At a scientific level, it's fascinating," Cuthbert says. "We're trying to understand how this memory gets formed, and why some get the disorder and other people have the same experience and don't get the disorder. And how can we help people to cure it?"
Indelible memoriesWhy are these memories so deeply burned into our brains? Animal models have provided invaluable clues.
One pioneer in this area is professor Bruce Overmier, who developed the concept of "learned helplessness" along with his colleague Martin Seligman in the 1960s when they were at the University of Pennsylvania. They found that animals exposed to inescapable shocks subsequently were impaired in learning how to avoid them. Learned helplessness became a widely known and often-cited model for depression and PTSD because it showed how exposure to severe trauma causes lasting distress and a reduced ability to cope.
More recently, associate professor Jonathan Gewirtz (Right) has shown just how permanent traumatic memories can be. Gewirtz conditions lab animals to associate a tone or light with a painful electric shock. Soon these stimuli trigger a stress response even without a shock. Blood pressure increases, stress hormones flood the body, and the "startle reflex" becomes chronic. A fearful rat -- just like a nervous person -- will literally jump higher than a normal one.
Gewirtz has shown that these shocks rapidly produce traumatic memories that may last a lifetime. "It's indelible," he says. "No matter how long the rat is tested, those memories don't go away."
Gewirtz believes these rats' responses to shocks provide models for what occurs in humans with PTSD or phobias. His research seeks to identify brain structures and molecular mechanisms involved in the formation and retrieval of such fearful memories. It also examines methods of treatment, such as anxiety-reducing drugs, or use of "exposure therapy," which repeats the triggering event without painful consequences.
"Can we alleviate those states?" asks Gewirtz. "That's essentially what we're trying to do in animal models. If we can find the right treatments, then we want to try them out on people, too. That could help people with anxiety disorders, depression (which is often triggered by stress), and drug addiction."
The right stuffLike laboratory rats, some people are more resilient than others, and less susceptible to PTSD. One person may survive a plane crash and show relatively few aftereffects, while the passenger in the next seat may develop full-blown PTSD. Trauma, like pain, is filtered through cognitive and emotional processes that may raise or lower reaction thresholds.
Professor Emerita Gloria Leon has done extensive research on survivors of traumatic ordeals such as Vietnam combat, Holocaust concentration camps, and the Chernobyl and Three Mile Island nuclear accidents. Part of her research focuses on what makes certain people more resistant to stress and trauma, or what Leon calls "the right mix of the right stuff."
According to Leon, some of these differences are innate. Newborn infants react with a range of individual differences in heart rates, digestive disturbances, or crying when they are startled by a loud noise. Similarly, adults respond in varied ways to extreme stress. Some become hyperactive, others immobile. Some may tell themselves there's no hope while others think optimistically and work to resolve the problem.
Yet no one is immune, says Leon: "Every person has a breaking point."
But how do we return from that breaking point? This is a question that drives Patricia Frazier's (Left) research on adjustment to stressful or traumatic events, particularly sexual assault.
Frazier identifies three key coping strategies. First, identifying social support is crucial -- even if you don't use it. "It's not so much the support you receive, but how much you perceive that you have," says Frazier. "You don't necessarily need to call up Betty and talk to her. But just knowing Betty is there helps. People facing a trauma who don't have anyone they could call are particularly likely to be distressed."
A second coping strategy is to focus on what can be done now rather than dwelling on what went wrong in the past. Ruminating, says Frazier, is natural -- but, after a certain point, ineffective. "We worry about the past and we worry about the future, and we can't do anything about them," she says. "We can do something about the present."
Frazier's research suggests that focusing on the past not only keeps one mired there but also may even lead to more distress, perhaps because it forces continual re-enactment of the event. In one review, Frazier and her co-authors examined the distinctions between past control (could I have prevented this?), future control (can I keep this from happening again?), and present control (what can I do now?). The more people thought about how a traumatic event could have been "undone," the more distress they reported.
Frazier's research shows that blaming doesn't help, either. In a longitudinal analysis of 171 sexual assault survivors that was published in the Journal of Personality and Social Psychology, survivors who focused on blame (blaming themselves or the rapist) reported the most distress during the two years following the assault; those who focused on the present recovery process fared better.
The third and very effective strategy identified in Frazier's research is "cognitive restructuring," or reframing how we perceive events. A woman who has been sexually assaulted can say, "I'm damaged beyond repair and I will never be able to get over this," or she can say, "I'm going to use this experience to educate others about sexual assault." The second strategy is more likely to reduce distress, says Frazier, because "you're taking control of the stressful event."
Focus on recoveryBack at the V.A. Medical Center, psychologists like Engdahl are helping trauma survivors do just that -- take control. Besides treating patients, he and other University of Minnesota psychologists are researching topics such as personal growth and healing after traumatic events, and are exploring the diagnostic potential of neuroimaging.
Sadly, this work won't end anytime soon. Data from past wars suggest that one-third of the veterans of Iraq and Afghanistan will develop PTSD during their lifetimes, says Engdahl. Two-thirds of those with serious wounds will suffer from the disorder.
Most people, says Engdahl, are resilient and resolve their problems over time. Yet his research shows that severe trauma leaves lasting scars in most people. In one study, Engdahl and his colleagues examined a group of 262 veterans who had been prisoners of war during World War II or the Korean War. More than half the men had PTSD during their lifetimes, and 29 percent still did. Among the most severely traumatized group -- former POWs of Japan -- 84 percent had grappled with PTSD at some point in their lives and 59 percent still did half a century later.
"If trauma exposure is severe or prolonged, most people will be badly affected in ways we have come to recognize as PTSD," Engdahl says. "Many will be affected for a very long time."
Yet the profession has come a long way. Today there's a strong emphasis on early screening, treatment, and destigmatization -- and it's not just young veterans who are reaping the benefits.
"Some of the people being evaluated for post-traumatic stress disorder and getting into treatment are World War II veterans coming in for the first time in 60 years," says Engdahl. "We tell them, 'Let's see if we can help you.'"