This study is a prospective, randomized, controlled (randomized, parallel group, concealed allocation), double-blinded trial. All depression patients undergoing breast cancer operation will be randomized 1:1 to the treatment intervention with general anesthesia as an adjunct to esketamine or saline. The objective of the trial is to evaluate the postoperative depression、gut microbiota、bispectral index data of patients undergoing breast cancer operation with esketamine or saline.

For female patients, breast cancer patients have a high risk of developing depression, and approximately 20%-45% of breast cancer patients suffer from postoperative depression. Esketamine is an anesthetic in analgesia, and has presently become more and more popular for treating anti-depression, particularly for resistant depression.

This study is a prospective, randomized, controlled (randomized, parallel group, concealed allocation), double-blinded trial. All depression patients undergoing breast cancer operation will be randomized 1:1 to the treatment intervention with general anesthesia as an adjunct to esketamine or saline. The objective of the trial is to evaluate the postoperative depression、gut microbiota、bispectral index data of patients undergoing breast cancer operation with esketamine or saline

Inclusion Criteria:

• At least18 years and pre-menopausal;
• scheduled to undergo elective breast cancer operation;
• American Society of Anaesthesiologists (ASA) risk classification I-II.
• Montgomery-asberg Depression Rating Scale (MADRS) score ≥22

Exclusion Criteria:

• Cognitive difficulties
• Partial or complete gastrectomy
• Previous esophageal surgery
• Inability to conform to the study's requirements
• Ongoing participation or participation in another study <1 month ago

female