In the wake of the 9/11 attacks and the 2001 anthrax letters, the U.S. public has been bombarded with information about the dangers of bioterrorism. But some say that the messages often overstate the risks and hurt more than they help. Now, these critics have some data to back up their claim: A small study shows that reading scary information about bioterrorism can actually lead to increased anxiety and stress levels.
People learn about bioterrorism in many ways, from government advice to buy duct tape and plastic sheets to newspaper articles and even blockbuster movies. Many believe this information is vital to prepare the public for a growing threat. But epidemiologist Hillel Cohen of Albert Einstein College of Medicine in New York City says that, in contrast to messages about drunk driving or smoking, it's often not clear how the public is supposed to change their behavior in response to bioterror warnings. The advice to buy duct tape was highly controversial, for instance, as was a large drive to vaccinate Americans against smallpox launched late 2002. That makes it even more important to evaluate the warnings' downsides, he says--something that isn't usually done.
Cohen's team recruited 116 graduate students, 96% of whom considered bioterrorism a likely threat. The group was given a standard anxiety test. Half of the volunteers were then asked to read about a 17-year-old girl dying a horrible death from an engineered virus and an expert warning that such threats are real. (The text was based on The Cobra Event, a novel by Richard Preston that former president Bill Clinton cited when he announced the first bioterror preparedness program.) The other half was given a message of equal length that portrayed bioterrorism as a minor risk.
The subjects who had read the scary message scored significantly higher on a post-test, whereas the control group was less anxious after reading their message. Writing in International Quarterly of Community Health Education, the team notes that anxiety and stress are known to lead to other problems and concludes that bioterrorism messages may be harmful, especially to people susceptible to stress-induced health problems.
"They are right to conclude that these [public health messages] do need careful analysis and justification," says Ruth Faden, a bioterrorism expert at the Johns Hopkins University Berman Institute of Bioethics in Baltimore, Maryland. But the study was small and only looked for an immediate effect, Faden cautions; whether the messages pose an ongoing mental health hazard "is an open question."