Researcher Finds 9/11 Attacks Led to New Understanding of Mass Trauma

Out of the wreckage of the World Trade Center attacks and the events of 9/11 came some of the first large-scale research of mass trauma. The resulting findings have led to a broader understanding of how post-traumatic stress disorder can affect hundreds of thousands of people, not just individuals.

Dr. Sandro Galea, chair of the epidemiology department at the Mailman School of Public Health, is one of the leading researchers on the topic, having written some 50 articles on the subject of 9/11 and trauma.

Large-scale catastrophes such as war, earthquakes or floods typically occur where the devastation prevents health professionals from gaining access to the area and its victims. The events of 9/11 were different, he said, providing an unexpected opportunity for researchers. “There had been a number of studies, but never of an event the magnitude of 9/11, in a country that could mount the kind of research activities that were mounted in the U.S.,” said Galea, who specializes in the role traumatic events play in the health of populations. Some 350 studies ultimately were done involving 9/11, many of them by researchers at or affiliated with Columbia.

In New York City, where the physical damage was confined to lower Manhattan, mental health professionals could act almost as quickly as first responders. “It was a combination of a dramatically large event in a place which could mount a research program, and it came at a time in our scientific understanding when we were ready to look for the clues to psychopathology on a large scale,” Galea said. “A lot of people who know a lot about trauma and its consequences were very interested.”

Diagnoses of post-traumatic stress disorder, which can occur among those who have witnessed or experienced events that provoke feelings of intense fear, helplessness or horror, typically can’t take place until at least a month after the triggering event. The first 9/11 trauma study began on Oct. 29, 2001, five weeks after the attacks. “We wanted to be in the field quickly to assess short-term consequences,” Galea said.

The findings are widely known now, a decade later, and include the following: that a wide range of people, including survivors, rescue workers and those living in the area reported symptoms of post-traumatic stress; that nearly 96 percent of survivors reported at least one symptom of post-traumatic stress disorder two to three years after the attack; that the prevalence of depression, anxiety, substance abuse and PTSD in the New York area all were higher than they were before the attacks; that people closer to the Twin Towers that day were at higher risk for PTSD; and that the majority of survivors still experienced multiple symptoms of PTSD two to three years after the attacks.

PTSD has existed throughout history, of course. Indeed, descriptions of what today sound like the disorder can be found in Homer’s The Iliad. In 1980, it appeared for the first time in the Diagnostic and Statistical Model of Mental Disorders, the textbook used by mental health professionals to help classify and treat patients. “Ultimately, the diagnosis came about due to awareness of this pathology in soldiers who served in Vietnam,” Galea said. “They had a constellation of symptoms that came to be known as PTSD.”

Until recently, much of the research on trauma and mental health focused on individuals, but “I think it’s fair to say the 9/11 attacks helped galvanize research around the mass consequences of these traumatic events,” said Galea. “This resulted in a realization these large-scale events that affect so many people represent a different scale of need and require a different scale of response.”

Not all large-scale disasters are the same, and different events affect people, and populations, differently. The aftermath of 9/11 resulted in more PTSD diagnoses because so many people actually saw the trauma, Galea notes. In contrast, after the 2004 train bombings in Madrid that killed 191 people and injured several thousand, researchers, including Galea, found more depression than PTSD. “That was a large event, but not particularly visible,” he said.

Galea’s work has extended the research he started after 9/11. “We went on to conduct studies looking at the consequences of other large events both in the U.S. and in other countries,” he said. He has also begun to explore how trauma manifests as mental illness, or, as he says, “how stress gets under the skin.” This has included work on molecular changes at the cellular level that may, in response to the experience of trauma, explain the symptoms we have come to call PTSD.

—by Bridget O'Brian

August 31, 2011