This randomized controlled trial aims to evaluate the effect of a structured self-affirmation intervention on pain, depression, anxiety, and stress levels in patients undergoing mastectomy. The study will be conducted in two parallel groups, with the intervention group listening to an audio recording of positive self-affirmation statements. Primary outcomes will be assessed using the Visual Analog Scale and the Depression Anxiety Stress Scale (DASS-21). The goal is to provide evidence-based strategies to reduce psychosocial burden after mastectomy.

This randomized controlled trial is designed to evaluate the effect of a structured self-affirmation intervention on pain, depression, anxiety, and stress levels in patients undergoing mastectomy. Breast cancer is the most commonly diagnosed cancer among women worldwide, and mastectomy, a standard surgical treatment, often results in significant physical and psychosocial consequences. The loss of a breast, perceived as a symbolic part of femininity, can severely impact body image and self-esteem, leading to psychological distress symptoms such as depression, anxiety, and stress, as well as chronic pain. These adverse effects not only reduce quality of life but also negatively influence treatment adherence and long-term survival.

In this study, participants in the intervention group will listen to an audio recording containing positive self-affirmation statements accompanied by soothing background sounds such as birds chirping and flowing water. The recording, prepared by a certified practitioner, lasts approximately 5 minutes and 40 seconds. Patients will be instructed to listen to the recording at least once daily, with encouragement to listen more frequently if desired. The control group will receive standard care without any additional intervention. Primary outcomes will be assessed using the Visual Analog Scale (VAS) for pain and the Depression Anxiety Stress Scale (DASS-21) for psychological distress. The ultimate goal of this trial is to develop an evidence-based nursing and psychosocial support protocol that can be integrated into postoperative care to reduce psychosocial burden and improve well-being in mastectomy patients.

Inclusion Criteria:

• Age 18 years or older
• Female patients who have undergone mastectomy surgery
• Able to speak and understand Turkish
• Provides informed consent and agrees to participate voluntarily

Exclusion Criteria:

• Diagnosed psychiatric disorder
• Hearing impairment that prevents listening to the audio intervention

Individual participant data will not be shared due to confidentiality and ethical considerations.

This study is open-label. Masking was not feasible due to the nature of the behavioral intervention (audio recording of self-affirmation statements). Both participants and investigators were aware of group assignments.