Introduction: The present study aims to investigate the effectiveness of the Unified Protocol for Transdiagnostic Treatment of Emotional Disorders (UP) for women with breast cancer. Methods: We conducted a pilot randomized controlled trial in which women with breast cancer were allocated to a 9-week Unified Protocol for Transdiagnostic Treatment of Emotional Disorders (UP) (n = 14) or a waitlist-control condition (n = 15). All patients completed the Beck Depression Scale (BDI-II), Beck Anxiety Scale (BAI), Depression, Anxiety and Stress Scale (DASS-21), Cognitive Flexibility Inventory, Cognitive Emotion Regulation Strategies Scale (CERQ) emotional awareness level scale (LEAS), and The EORTC breast cancer-specific quality of life questionnaire (EORTC QLQ-BR23) pre-and post-intervention. Results: Significant reductions in depressive, anxiety, and stress symptoms as well as maladaptive emotional regulation strategies, were observed within the UP condition from baseline to post-treatment. Participants in the UP condition showed increased adaptive strategies of emotional regulation, cognitive flexibility, mindful emotional awareness, and quality of life compared to the waitlist-control condition. Conclusions: Participants’ performance may improve by any study manipulation, though Changes in significant differences within subjects suggest that imposed by the researcher. These results provide preliminary evidence for the utility of using the UP to reduction of psychological dysfunction and improving the quality of life for women with breast cancer.

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