The multiple mediating effects of cancer threat appraisal and quality of life on the association between mindfulness and depression for colorectal cancer survivors.

Objective: This study explored the multiple mediating effects of cancer threat appraisal, functional status, and symptom distress on the association between mindfulness and depression in colorectal cancer (CRC) patients at the transition stage after completing cancer treatments.

Methods: A total of 90 CRC survivors who received cancer treatments within 3 months participated in this cross-sectional study. The functional status and symptom distress (EORTC-C30 and EORTC CR29), dispositional mindfulness (Five Facet Mindfulness Questionnaire), cancer threat appraisal ( Constructed Meaning Scale), and depressive symptoms (Beck Depression Inventory-II scale) were collected. The mediation and moderation analyses were conducted using the PROCESS macros for SPSS.

Results: Survivors' dispositional mindfulness (γ = -0.49, p < 0.001) and cancer threat appraisal (γ = -0.59, p < 0.001) were significantly associated with depressive symptoms. Simple mediation analysis indicated that cancer threat appraisal mediated the relationship between dispositional mindfulness and depression (β = -0.02, 95% CI = -0.04 to -0.001). The multiple mediated analysis identified the path between dispositional mindfulness and depression via cancer threat appraisal and colorectal symptom distress (β = -0.01, 95% CI = -0.03 to -0.01). In the mediated moderation model, the path between dispositional mindfulness and depression via colorectal function was moderated by cancer threat appraisal (β = -0.02, 95% CI = -0.05 to -0.004).

Conclusions: The two cognitive mechanisms of reducing CRC survivors' depression are as follows: (1) dispositional mindfulness reducing the appraisal of cancer as a threat and increasing positive perceptions of CRC symptoms and (2) the cancer threat appraisal buffered the impacts of CRC's mindfulness and colorectal function on depressive symptoms. Developing mindfulness with cognitive training is recommended for improving depressive symptoms among CRC patients in the transition period.