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Sources of anticipatory emotional distress in women receiving chemotherapy for breast cancer.

BACKGROUND
The contribution of classical conditioning processes to patients' distress before chemotherapy infusions (anticipatory distress) was compared to other potential sources of distress (e.g., trait anxiety). We hypothesized that posttreatment distress (putative unconditioned response) would become a stronger predictor of anticipatory distress as patients underwent more treatment infusions (putative conditioning trials).


MATERIALS AND METHODS
Fifty women with early stage breast cancer, undergoing standard chemotherapy, completed questionnaires in the clinic prior to each of eight consecutive treatment infusions, as well as telephone interviews to assess side effects following infusions.


RESULTS
Consistent with the conditioning hypothesis, posttreatment distress became significantly related to anticipatory distress at the fourth infusion and became the strongest predictor by the sixth. Path analysis indicated that posttreatment distress had a direct influence on anticipatory distress, and that trait anxiety had an indirect influence by influencing apprehension about chemotherapy which, in turn, directly predicted anticipatory distress.


CONCLUSIONS
The results of the present study contribute to an emerging view of anticipatory distress as a conditioned response in chemotherapy patients. Results demonstrate that conditioning factors may be one of the strongest predictors of anticipatory distress in the later phases of chemotherapy treatment.