The impact of behavioral activation on depressive symptoms in colorectal cancer patients within a medical environment: the mediating role of physical activity.

Colorectal cancer (CRC) treatment often affects patients' quality of life, leading to depressive symptoms. Behavioral activation (BA) therapy, which increases engagement by enhancing positive reinforcement and reducing avoidance, has shown potential in managing these symptoms. Physical activity (PA) is also known to alleviate depression, though its role as a mediator in BA's effectiveness remains unclear. This clinical trial was retrospectively registered in ClinicalTrials.gov on April 5, 2024 (Effects of Behavioral Activation on Negative Emotions, Cancer-related Symptoms and Clinical Indicators in Cancer Patients, NCT06348940). This study explores PA's mediating effect within BA interventions. A total of 109 CRC patients with depressive symptoms were randomly assigned to a BA group (n=52) or a Usual Care (UC) group (n=57). Assessments occurred at baseline (T0), after the fourth session (T1), and post-intervention (T2). The BA group showed significant improvement compared to the UC group. Repeated measures ANOVA confirmed BA's effectiveness in reducing depressive symptoms, improving quality of life, alleviating psychological distress, increasing activation, and raising PA levels. PA changes accounted for 36.91% of the intervention's total effect on depression reduction. BA effectively reduces depression and enhances life quality in CRC patients. Changes in PA intensity are significantly associated with depression reduction, suggesting PA's mediating role in BA's impact. Incorporating PA into BA may enhance therapeutic outcomes for CRC patients with depression.