Patients undergoing breast cancer surgery frequently experience perioperative anxiety and depression, which can adversely affect recovery and quality of life. This study evaluates the efficacy of a single 30-minute intraoperative taVNS session in mitigating these negative emotions and improving postoperative outcomes. Patients will be randomized to receive either active taVNS or sham stimulation after anesthesia induction. The primary outcome is the incidence of depressive symptoms within 3 days postoperatively. Secondary outcomes include anxiety, pain, PONV, sleep quality, and recovery parameters.