Patients' pretreatment expectations of chemotherapy-related nausea are an independent predictor of anticipatory nausea

Based on extensive research with animals, classical conditioning theorists have come to regard contingency as the primary factor in the development of conditioned responses. However recent experimental work with humans has su ggested the possibility that participant expectations may also directly con tribute to the development of conditioned responses. To date, this phenomen on has not been investigated in clinical settings. Anticipatory nausea (AN) in chemotherapy patients, widely viewed as the best established example of classical conditioning in clinical medicine, provides an opportunity to ex amine the contributions of patient expectations to the development of a con ditioned response outside the laboratory. The present study of 59 breast ca ncer patients supported the hypothesis that pretreatment patient expectatio ns make a significant (p <.03) contribution to the development of AN after statistically controlling for the strongest conditioning predictor, conting ency. These data imply that patient expectations should be considered when evaluating conditioned responses to aversive medical treatments.