The US military is leading the hunt for additional biological markers of resilience. Since 2008 — driven in part by soaring suicide rates among soldiers — the US Army has collaborated with the National Institute of Mental Health and several academic institutions on a US$65-million project called Army STARRS (the Study to Assess Risk and Resilience in Servicemembers). The project has many parts, including a retrospective look at de-identified medical and administrative records for 1.6 million soldiers, in search of early warnings of suicide, PTSD and other mental-health problems. STARRS scientists are also collecting data — such as blood samples, medical histories and cognitive testing results — on tens of thousands of current soldiers. The researchers expect to publish their first findings early next year.
The military also funds research into animal models of resilience. Most rodents will quickly learn to associate painful foot shocks with a certain cue, such as a tone or a specific cage. After they have learned the association, the rodents freeze on experiencing the cue, even without the shock. Several years ago, Abraham Palmer, a geneticist now at the University of Chicago in Illinois, made a line of resilient mice by selectively breeding mice that froze for abnormally short periods of time. After about four generations, he had mice that froze for about half the time of typical animals. The effect was not due to a difference in pain sensitivity or general learning ability. This month, Luke Johnson, a neuroscientist at the Uniformed Services University, will present data at the Society for Neuroscience meeting in New Orleans, Louisiana, showing that these mice have uncommonly low activity in the amygdala and hippocampus, consistent with human studies of PTSD resilience. They also have low levels of corticosterone, a stress hormone, in their urine.
“They have a quieter system, even at rest,” says Johnson. “It suggests that there are underlying biological traits that are associated with the capacity of the animal for fear memory.” In future experiments, Johnson plans to use the mice to study NPY and potential new therapies.
Ebaugh, who now specializes in therapy for trauma victims, agrees that drug-based treatments could aid in recovery. But some people may find relief elsewhere. Religious practices — especially those that emphasize altruism, community and having a purpose in life — have been found to help trauma victims to overcome PTSD. Ebaugh says that yoga, meditation, natural remedies and acupuncture worked for her.
Today, she buys groceries at the plaza where she was abducted, and she drives over the bridge she was thrown from as though it were any other road. She says that she has forgiven the man who abducted her. When she reflects on what he did, it's not with anger, sadness or fear. “It doesn't feel like it affects my life at all at this point, at least not in a negative way,” she says. “In a positive way, it's been a huge teacher.”