The study also found that traumatic event exposure can create changes in the human brain that cause people to be too sensitive and to overreact to innocent or harmless facial gestures many years after the trauma.
Healthy people who experience traumatic events may actually be having subsequent brain and behavioral issues that are not currently considered clinical disorders.
However, they can become worse over the long term.
Of the groups of individuals studied, one group, which was closest to the World Trade Center on 9/11 had reported more current symptoms in comparison to those further away from the traumatic event. Their symptoms included increased irritability, difficulty in sleeping and hypervigilance. They also felt that they now avoided many things they used to do, such as going downtown. Another factor included problems with nightmares and recurring distressful memories.
Magnetic resonance imaging scans were taken to determine the brain activities of the study participants.
Findings showed that a person's heightened reactivity after highly intensive traumatic events may not be slow in recovery, which can probably be blamed for the overreactions of these individuals' emotions and behaviors in response to everyday events.
"Our findings suggest that there may be long-term neurobiological correlates of trauma exposure, even in people who appear resilient. Since these effects were observable using mild, standardized emotional stimuli (not specific trauma reminders), they may extend further into everyday life than previously thought," said Barbara Ganzel, PhD.
"We have known for a long time that trauma exposure can lead to subsequent vulnerability to mental health disorders years after the trauma. This research is giving us clues about the biology underlying that vulnerability. Knowing what's going on will give us a better idea how to help," stated Dr. Ganzel.
This study was published in the May issue of "Emotion," a publication of the APA.
