• Fully understand the purpose, content, and potential adverse reactions of this trial, voluntarily participate in the clinical trial and sign a written informed consent form, able to complete the entire trial process as required and comply with the trial regulations;

• Gender unrestricted, at screening: 18 years old ≤ age ≤ 65 years old;

• Meet the DSM-5 (Diagnostic and Statistical Manual of Mental Disorders, 5th Edition) diagnostic criteria for depression according to the Mini International Neuropsychiatric Interview (M.I.N.I. 7.0.2), currently experiencing a single or multiple episodes;

• For first-episode patients, the duration of the current depressive episode must be ≥3 months; for recurrent patients, the duration of the current depressive episode must be ≥1 month (each month is counted as 30 days, the same applies below);

• During the screening and baseline periods, the total score on the Montgomery-Asberg Depression Rating Scale (MADRS) must be ≥26, and the Clinical Global Impression-Severity (CGI-S) score must be ≥4;

• At screening and baseline visits, the score on the first item (depressed mood) of the HAMD-17 scale must be ≥2;

• Female or male subjects of childbearing potential agree and commit to using effective contraception from the signing of the informed consent form until 3 months after the last administration of the trial drug.