As we remember the tragedy of 9/11, a new research study suggests the severity of a traumatic event can influence the mental health of individuals not directly exposed to the incident.
Experts evaluated how the attacks impacted the psychological processes of those not directly exposed to the event.
Researchers studied college students in Massachusetts and found that even those who were not directly connected to New York or Washington showed increased stress responses to run-of-the-mill visual images.
“Other studies have shown that the 9/11 attacks resulted in a wave of stress and anxiety across the United States,” said researcher Ivy Tso, a doctoral student in clinical psychology at the University of Michigan.
“Eight to 10 percent of the residents of New York City reported symptoms consistent with posttraumatic stress disorder (PTSD) and depression while 40 percent of Americans across the country experienced significant symptoms of stress related to the attacks.”
Study findings are published in the Journal of Traumatic Stress.
Tso and her colleagues’ study, which took place within one week of the attacks, assessed a sample of 31 university students in Boston who were not directly connected to the attacks in New York and therefore represented the wider American public.
Researchers evaluated the brain activity of the participants to detect signs of anxiety and stress as they were shown a series of 90 pictures.
Thirty of the pictures contained images of the attacks while the others were defined as either “negative” but not related to the attacks, or “neutral.”
“The results of our study indicate that participants’ brain wave responses during processing of the images deviated from normal in proportion to their self-report distress level directly related to the 9/11 attacks,” said Tso.
The abnormal brain activity is similar to what is observed in individuals with PTSD (e.g., diminished attention, hypervigilance, suppression of unwanted thoughts).
“This finding is significant as our participants were young, unmedicated, highly functional individuals and while their distress was clearly below clinical threshold, their brain responses to emotional information were affected the same way, though not to the same degree, as in PTSD,” concluded Tso.
“This makes us rethink whether distress reactions should be considered a spectrum of severity, rather than simply divided into normal vs. clinical categories.”