The influence of priming and pre-existing knowledge of chemotherapy-associated cognitive complaints on the reporting of such complaints in breast cancer patients.

Two hundred and sixty-one breast cancer patients were interviewed about cognitive problems and other cancer-related symptoms. Preceding the interview, half of the patients were primed with an introduction letter to the study in which the occurrence of cognitive complaints and its relation with chemotherapy was explicated. The remaining patients received a neutral letter that did not mention this relationship.

Our study shows that facilitating the accessibility of concepts related to chemotherapy-associated cognitive complaints directly increases the reporting of such complaints, in particular in patients without firsthand chemotherapy experience. This increase in prevalence of cognitive complaints following a chronically or temporarily accessible 'chemo-brain' schema has relevant implications for clinical practice and for scientific research in this area.

Patients with pre-existing knowledge about chemotherapy-associated cognitive problems reported more cognitive complaints (M=3.04) than patients without this knowledge (M=2.21; p<0.001). The priming letter increased the reporting of cognitive complaints only for patients without a history of chemotherapy (p<0.05). All effects were independent of negative affect, age and education level.

Many cancer patients report cognitive changes following chemotherapy. In social psychology, there is ample evidence that psychological and physical complaints can increase with increased accessibility of relevant schemata. The accessibility of related concepts in memory may be facilitated through priming or by pre-existing knowledge, resulting in an increase of reported complaints. We examined whether pre-existing knowledge of chemotherapy-associated cognitive problems and priming the 'chemo-brain' schema increase the reporting of cognitive complaints.