"A person's expectations can strongly affect how they respond to adversity – both subjectively and physiologically," said lead author Max E. Levine, Ph.D. "Being prepared for difficulty can benefit people greatly."
The study, designed to determine how expectations affect symptoms of nausea and motion sickness, found that participants who were led to expect considerable nausea actually fared better than those who weren't. The results are reported in the current issue of Psychosomatic Medicine.
Participants were 75 healthy college students who were assigned to one of three groups. All groups were given placebo, or "dummy" pills. One group was led to believe that the pill would protect them against the development of nausea and motion sickness. A second group was told that the pills would make their nausea worse. And, a third group was told that the pills were placebos and would have no effect whatsoever.
Participants sat on a stool inside a drum marked with vertical stripes – viewing the drum's rotation induced the illusion of self-motion. The drum was rotated at a constant speed for 16 minutes, unless participants asked that it be stopped early.
While the drum was rotating, an intercom system was used to ask participants about symptoms of nausea and motion sickness, including warmth, dizziness and drowsiness. Based on the reported severity of symptoms, a score was calculated for each participant. In addition, three electrodes placed on the surface of their abdomens detected the presence of any of the abnormal stomach activity that typically accompanies nausea.
The nausea scores of the "placebo-control group," those participants who were told the pills would have no effect, were about 2.5 times higher than the group that was warned the experience would be particularly unpleasant. In addition, the abnormal stomach activity that typically accompanies nausea was 30 percent higher in the control group.
"Surprisingly, symptoms of nausea and motion sickness were least severe among participants told their experience would be made more unpleasant by the drug," said Levine, an assistant professor of gastroenterology.
The authors hypothesize that once the drum began to rotate, the group that was told they should anticipate a sickening experience may have experienced something far more innocuous than they had expected.
"Those who unnecessarily braced themselves for a torturous ordeal may have been calmed or relaxed by what they experienced," wrote the authors.
Levine said the findings have implications for patients who experience nausea as part of an illness or treatment.
"Being prepared to experience a negative reaction to the drum was associated with less nausea and more normal stomach activity, suggesting that how patients are prepared for potentially adverse events can meaningfully affect their responses to them," he said. "If patients are informed about what they will likely be going through over the course of an illness or treatment, it may influence their ability to cope with the symptoms once they develop."
Levine said that if further research can demonstrate that expectations regarding the development of nausea can control the unpleasantness of the symptoms that develop, there could be profound implications for the treatment of people whose illness or treatment involves nausea.
Co-researchers were Robert M. Stern, Ph.D., with the Pennsylvania State University, and Kenneth L. Koch, M.D., with Wake Forest.
About Wake Forest University Baptist Medical Center: Wake Forest Baptist is an academic health system comprised of North Carolina Baptist Hospital and Wake Forest University Health Sciences, which operates the university's School of Medicine. The system comprises 1,282 acute care, psychiatric, rehabilitation and long-term care beds and is consistently ranked as one of "America's Best Hospitals" by U.S. News & World Report.
Last reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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