Distributed January 16, 2001
For Immediate Release
News Service Contact: Kristen Cole



Understanding panic disorder

People prefer to know when a stressful event is about to occur
Sixty percent of participants in a study led by Brown researchers expressed a preference for knowing when an anxiety-provoking event was about to occur.

PROVIDENCE, R.I. — Given the option, people would rather know when a stressful event is about to occur than not know, according to a new study led by Brown University researchers, whose findings provide insight into the management of panic disorder.

Sixty percent of the study participants expressed a preference to know when an anxiety-provoking event was about to occur. The rest were largely indifferent; only a small percentage preferred not to know. Predictability was especially sought by women with a high vulnerability to anxiety, of whom 90 percent preferred predictability.

“The real value of predictability isn’t necessarily when the aversive event is happening,” said Carl Lejuez, the study’s lead researcher and an assistant research professor of psychiatry and human behavior at Brown. “Predictability allows you to know there are ‘safe’ periods.”

Despite the assumption in clinical work that identifying precipitants to panic is central to cognitive and behavioral treatments for panic disorder, there have been few studies in humans that directly test that assumption, said Lejuez.

Anxiety-provoking events were created by administering participants 20 percent carbon dioxide-enriched air, which produces many of the same psychological and physiological responses people experience during panic attack, including breathlessness, a feeling of tightness in the chest, and sweaty palms.

Forty undergraduate students at West Virginia University without a diagnosed anxiety disorder were tested using air enriched with the CO2.

In the first phase of the study, participants were told that sometimes a tone would warn them CO2 was coming and sometimes there would be no warning. Before each trial, a computer screen displayed either the letter T, indicating that if CO2 were administered during that trial they would hear a tone first, or N, indicating that there would be no tone. In a second phase of the study, participants could chose whether the CO2 would be predictable or unpredictable.

Although only individuals without anxiety disorders were studied, researchers found that study participants with the greatest vulnerability to anxiety (as determined by the way in which they answered a written questionnaire) were more likely to prefer and choose predict-able administrations of CO2 than less vulnerable participants.

In addition, women were twice as likely as men to prefer and choose predictable over unpredictable CO2 administrations. Other studies have found that women are at greater risk for experiencing panic attacks and developing panic disorder, according to Lejuez. Also, women have been shown to be more likely than men to seek information regarding unpleasant events.

Lejuez conducted the research with Michael Zvolensky of Brown University, Georg Eifert of West Virginia University, and Jerry Richards of the State University of New York–Buffalo. Their findings appeared in the December issue of the American Psychological Association’s Journal of Experimental Psychology: Applied. The next step in this line of research will be to study patients with panic disorders, said Lejuez. Additional research may also determine the exact mechanisms through which predictability offers its benefits.

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