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 majordepressive 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 periodmeet 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 byfemale sexual partners

Exclusion Criteria:

1. The researchers determined that it was refractory depression [defined as in acurrent depressive episode or a previous depressive episode, After 2 or moreantidepressants, a sufficient amount (in the maximum recommendation of themanual), a course of foot therapy (at least even Continued medication for 4-6weeks) ineffective after treatment] 2. The MADRS score improved by ≥ 25% atbaseline compared with the screening period.

2. Hospitalization in a psychiatric hospital during a current depressive episode

3. There is a clinically significant risk of suicide or self-harm and harm toothers 5. Screening patients tested positive for substance abuse 6. In theinvestigator's judgment, there are any clinically significant oncology,hematology, or internal diseases that are not suitable for entry into the studySecretory/metabolic, cardiovascular, respiratory, kidney, liver,gastrointestinal, infectious or nervous system fever Or suffer from an unstableor progressive chronic disease 7. hypertension 8. Hypothyroidism orhyperthyroidism, except for the following cases: receiving stable medicationwith 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 ）) 9Bupropion, dextromethorphan, opioids (such as codeine), or any of the studydrugs Allergic to other ingredients 10. Presence of a history of intolerance tobupropion or dextromethorphan 11. People living with HIV, or testing positivefor HIV during screening 12. Screening period hepatitis virology test positive

4. 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 forparticipating in this clinical study