Clinical Research Directory

Inclusion Criteria: * Male and female outpatients aged 18-65 years (inclusive). * Diagnosis of Major Depressive Disorder (MDD) according to DSM-5 criteria ( without psychotic features). * Hamilton Depression Rating Scale (HAM-D17) total score ≥ 22 at screening and baseline visits, with item 1 (depressed mood) score ≥ 2. * Clinical Global Impression-Severity (CGI-S) score ≥ 4 at screening and baseline. * Negative pregnancy test for women of childbearing potential. * Willingness to use effective contraception during the trial and for 3 months after the last dose. * Voluntary participation and signed informed consent. Exclusion Criteria: * Duration of the current depressive episode in first-episode patients \< 3 months. * Treatment-resistant depression (failure of ≥ 2 adequate antidepressant treatments). * Other psychiatric disorders (e.g., schizophrenia, bipolar disorder, anxiety disorders). * History of severe neurological diseases, epilepsy, or significant head trauma. * Unstable or severe cardiovascular, gastrointestinal, or endocrine diseases. * History of malignancy within the past 2 years. * History of increased intraocular pressure or untreated narrow-angle glaucoma. * Abnormal thyroid function not adequately controlled. * History of severe drug allergies or hypersensitivity to duloxetine or excipients. * Suicide attempt within the past year or significant suicide risk. * Substance abuse within the past year or positive at screening drug test. * Alcohol abuse (≥ 14 units/week) within the past year. * Previous treatment with duloxetine without adequate response. * Normative use of antidepressants within 2 weeks prior to screening. * Use of CYP2D6 or CYP1A2 potent inhibitors/inducers within 2 weeks prior to screening. * Participation in another clinical trial within the past 3 months. * Any condition deemed unsuitable by the investigator.