A new study has explained why exposure to extremely stressful situations often leaves 'emotional scar' and why some people develop posttraumatic stress disorders and some do not.
Researchers at the Mount Sinai School of Medicine suggest that it has something to do with the way that we control the activity of the prefrontal cortex, a brain region thought to orchestrate our thoughts and actions.
During the study, the research team examined women who had been the victims of violent sexual assault, some of whom developed PTSD and others who did not develop any serious emotional symptoms afterwards.
Using a brain imaging technique, they evaluated the ability of these women to voluntarily modify their own responses to unpleasant emotional stimuli and found that it was the trauma history itself, not how well they endured this sort of trauma that influenced their ability to dampen subsequent emotional responses.
The ability of the subjects to amplify their emotional responses to unpleasant stimuli was related to psychological outcome after the sexual assault.
The resilient individuals, that is, those who endured sexual assault without developing emotional symptoms, were able to enhance the activation of emotional brain circuitry in response to unpleasant stimuli more than either those with PTSD or healthy controls who had never experienced a serious sexual assault.
"This raises the possibility that the ability to focus on negative emotions permits the engagement of cognitive strategies for extinguishing negative emotional responses, and that this ability might be related to resilience," said corresponding author Dr. Antonia New.
"This is important, since it has implications for how we might enhance resilience," New added.
These findings suggest that exposure to extremely stressful situations may influence the capacity to be resilient to the impact of subsequent stressors, even when one does not develop PTSD.
"These data seem to support an idea that has emerged from clinical descriptions of resilient people, i.e., that people who are resilient are able to be flexible in the way that they respond to changing emotional contexts," said Dr. John Krystal, Editor of Biological Psychiatry.
"It would be helpful to know how we can enhance the flexible activation of these prefrontal cortex networks in people with compromised resilience," Krystal added.
The study appears in Biological Psychiatry.