A Trial of Dextromethorphan and Bupropion Sustained-Release Tablets in Patients With Major Depressive Disorder

Inclusion Criteria: 1. Male or female, Age 18 - 65, inclusive 2. Currently meets DSM-5 diagnosis of MDD without psychotic features, Current major depressive episode of at least 4 weeks in duration at screening 3. Identified as MDD by Mini-international Neuropsychiatric interview (M.I.N.I.) 4. MADRS score ≥25 and CGI-S ≥4 at screening and baseline 5. The results of physical examination and laboratory tests during the screening period meet the test requirements 6. Body Mass Index between 18 and 40 kg/m2, inclusive 7. For male subjects, use of an adequate method of birth control by the subject and by female sexual partners Exclusion Criteria: * 1\. The researchers determined that it was refractory depression \[defined as in a current depressive episode or a previous depressive episode, After 2 or more antidepressants, a sufficient amount (in the maximum recommendation of the manual), a course of foot therapy (at least even Continued medication for 4-6 weeks) ineffective after treatment\] 2. The MADRS score improved by ≥ 25% at baseline compared with the screening period. 3\. Hospitalization in a psychiatric hospital during a current depressive episode 4. There is a clinically significant risk of suicide or self-harm and harm to others 5. Screening patients tested positive for substance abuse 6. In the investigator's judgment, there are any clinically significant oncology, hematology, or internal diseases that are not suitable for entry into the study Secretory/metabolic, cardiovascular, respiratory, kidney, liver, gastrointestinal, infectious or nervous system fever Or suffer from an unstable or progressive chronic disease 7. hypertension 8. Hypothyroidism or hyperthyroidism, except for the following cases: receiving stable medication with no change in dose for at least 1 month before screening (serum TSH must be \> 0.75×LLN（ Lower Limit of Normal ） and \< 1.25×ULN（Upper Limit of Normal ）) 9 Bupropion, dextromethorphan, opioids (such as codeine), or any of the study drugs Allergic to other ingredients 10. Presence of a history of intolerance to bupropion or dextromethorphan 11. People living with HIV, or testing positive for HIV during screening 12. Screening period hepatitis virology test positive 13. Liver enzyme test results during the screening period (total bilirubin, aspartate aminotransferase and/or alanine aminotransferase) \> 2.0 × ULN 14. According to the investigator's judgment, other conditions are not suitable for participating in this clinical study