The role of depression in the relationship between cognitive decline and quality of life among breast cancer patients.

ABSTRACT

PURPOSE: Cancer patients who underwent chemotherapy experience cognitive decline, which, in turn, negatively impacts quality of life (QoL). Depression is considered a psychological factor that is negatively associated with the QoL of cancer patients. However, the relationships among cognitive functioning, depression, and QoL in breast cancer patients are under-researched in the literature. The aim of this cross-sectional study was to identify the role of depression in the relationship between cognitive functioning and QoL among breast cancer patients. METHODS: One hundred thirty breast cancer patients who underwent primary treatment participated. Participants completed the Functional Assessment of Cancer Therapy-Cognitive Function version 3, the Montreal Cognitive Assessment, the Beck Depression Inventory-II, and the Functional Assessment of Cancer Therapy-Breast Scale. The data were analyzed using multiple regression according to Baron and Kenny's strategies and the Sobel test. RESULTS: Subjective and objective cognitive functioning and depression were statistically significant predictors of QoL in breast cancer patients. Depression played a partial mediating role in the relationship between objective cognitive functioning and QoL and between subjective cognitive functioning and QoL. Additionally, the Sobel test demonstrated that depression had a significant partial mediating effect between subjective cognitive functioning and QoL (Z = 4.91, p < 0.001) and between objective cognitive functioning and QoL (Z = 2.62, p = 0.009). CONCLUSIONS: The findings indicated that depression could influence the association between cognitive functioning and QoL in breast cancer patients. Healthcare providers should develop an intervention focused on decreasing depression to evaluate the effectiveness of improving quality of life for breast cancer patients with cognitive dysfunction.