A more nuanced view of trauma

David Dobbs / New York Times News Service /

Many if not most survivors of combat, torture and other traumatic events rebound to live full, normal lives. Now, a significant body of work suggests that the environment just after the event, particularly other people’s responses, may be just as crucial to a person’s outlook as the event itself.

Psychological trauma dims tens of millions of lives around the world and helps create costs of at least $42 billion a year in the United States alone. But what is trauma, exactly?

Both culturally and medically, we have long seen it as arising from a single, identifiable disruption. You witness a shattering event, or fall victim to it — and as the poet Walter de la Mare put it, “the human brain works slowly: first the blow, hours afterward the bruise.” The world returns more or less to normal, but you do not.

In 1980, the Diagnostic and Statistical Manual of Mental Disorders defined trauma as “a recognizable stressor that would evoke significant symptoms of distress in almost everyone” — universally toxic, like a poison.

But it turns out that most trauma victims — even survivors of combat, torture or concentration camps — rebound to live full, normal lives. That has given rise to a more nuanced view of trauma — less a poison than an infectious agent, a challenge that most people overcome but that may defeat those weakened by past traumas, genetics or other factors.

Now, a significant body of work suggests that even this view is too narrow — that the environment just after the event, particularly other people’s responses, may be just as crucial as the event itself.

The idea was demonstrated vividly in two presentations this fall at the Interdisciplinary Conference on Culture, Mind and Brain at the University of California, Los Angeles. Each described reframing a classic model of traumatic experience — one in lab rats, the other in child soldiers.

In the first case, Paul Plotsky, a neurobiologist at Emory University, described what happened when he tweaked one of the most widely used models of how maternal separation affects young rats.

The model was created in the early 1990s by Plotsky himself to bring consistency to the way maternal separation is studied. Earlier experiments kept mother and pups apart anywhere from one to 24 hours; Plotsky reset those periods to 15 minutes (the amount of time rat mothers in the wild routinely leave their litters to get food) and 180 minutes (a traumatic separation, he says, because in the wild it would mean that “the mother became a meal or roadkill”).

After a 15-minute separation, a mother would typically sniff and lick each pup, then gather and feed them, all the while conversing with them in gentle, ultrasonic warbles. After a 180-minute separation, however, most mothers would dash about emitting panicky squeaks, often stomping on the pups or ignoring them. The pups too would squeak loudly. And for the rest of their lives, they had outsize physiological and behavioral reactions to stress and challenge.

This “15/180” model quickly became a standard, generating scores of studies showing that long separations created anxious rodents with permanent changes in stress-hormone activity, brain structure and many other measures. These findings became foundational to our view of trauma and its effects.

Then about five years ago, Plotsky was thinking about the mother’s post-separation panic when, he said, “it hit me: Maybe she views her environment as unsafe” because she and her pups are back in the same cage as the one they were taken from.

So he upgraded the simple cage to a complex one: a maze devised to test rats’ navigational skills. The separated rat family now reunited not in the kidnapping site but in the antechamber of an eight-room condo.

Now, even after 180-minute separations, things went fine. The mother would sniff the pups, check out a couple of rooms, then move everybody to one of them and coddle and nurse the pups much as she would after a 15-minute absence. Even if Plotsky separated the family again the next day (or even eight days in a row), she would do the same thing, usually choosing a new room.

But maybe the pups still suffered? Actually, no. Few showed any signs of trauma, either immediate or lasting. A separation that had been considered permanently scarring proved routine simply because the mother, having a more varied, secure environment in which to receive her pups, felt calmer and more in control, and she passed that on to the pups. Trauma seemed now to rise not from the separation alone but from the flavor of the reunion.

But that is rats in a lab. Does the same hold true for humans?

A study of former child soldiers in Nepal suggests that it may. Since 2006, Dr. Brandon Kohrt, a psychiatrist and medical anthropologist at George Washington University, has followed the fates of Nepalese children who returned to their villages after serving with the Maoist rebels during their country’s 1996-2006 civil war.

All 141 in the study, 5 to 14 years old when they joined the rebels, experienced violence and other events considered traumatic, aside from their separation from family. Yet their postwar mental health depended not on their exposure to war but on how their families and villages received them.

This finding is echoed in studies of U.S. soldiers returning home: PTSD runs higher among veterans who cannot reconnect with supportive people and new opportunities.