For the first time, acute stress responses to the attacks on the World Trade Center and the Pentagon have been linked to a 53 percent increased incidence in cardiovascular ailments over three years following 9/11. These findings persist even after considering health status before 9/11, degree of exposure to the attacks, and risk factors such as cholesterol problems, diabetes, smoking, and body weight. The results were especially strong among individuals reporting ongoing worry about terrorism after 9/11; these individuals were three to four times more likely to report a doctor-diagnosed heart problem two to three years after the attacks.

Our study is the first to show that even among people who had no personal connection to the victims, those who reported high levels of post-traumatic stress symptoms in the days following the 9/11 attacks were more than twice as likely to report being diagnosed by their doctors with cardiovascular ailments like high blood pressure, heart problems and stroke up to three years later, said Alison Holman, Professor in Nursing Science and lead researcher for the study, which is published in this month's Archives of General Psychiatry.

We must consider the potential public health impact of indirect exposure to extreme stress since the majority of our respondents were exposed to the attacks only by watching television, said Roxane Cohen Silver, Professor of Psychology and Social Behavior and Medicine. Our findings highlight the possibility that acute stress reactions may indicate subsequent vulnerability to potentially serious health problems.

The study involved a random sample of almost 2,000 adults from across the country that completed confidential surveys in the days and months following the September 11 attacks. Participants answered questions about acute responses to the attacks, ongoing worries about terrorism (e.g., I worry that an act of terrorism will personally affect me or someone in my family) and physician-diagnosed health ailments. The majority of the respondents reported watching the attacks on live television; one-third reported no live or direct exposure to the attacks, and a few reported direct exposures to the attacks. Follow-up surveys were conducted annually for three years.

Researchers analyzed survey participant feedback regarding their physical and mental health, worries about terrorism and lifetime exposure to traumatic events, such as divorce or abuse. The study concludes that psychological stress following the attacks led to an increase incidence of cardiovascular ailments among adults who had no known pre-existing cardiac condition.

This study, funded by the National Science Foundation, builds upon previous research by Silver and Holman into stress responses to the terrorist attacks of 9/11. In a report the researchers released in 2002, 17 percent of the U.S. population outside of New York City reported symptoms of post-traumatic stress two months after the attacks. This research shows that the psychological effects of a traumatic event are not limited to those who experience it directly, and that health consequences can be felt years after the event if appropriate treatment is not available to those who are at greatest risk.

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