Study to Explore the Effective Doses and to Assess the Safety and Efficacy of Hypidone Hydrochloride Tablets

A total of 240 major depressive disorder (MDD) subjects between the ages of 18-65 who have current major depressive disorder diagnosed by DSM-5 will be recruited, Eligible patients will be randomized with a 1:1:1:1 ratio into the 4 treatment arms to receive either Hypidone Hydrochloride tablets or placebo, and will be accepted into the protocol after review and providing voluntary written informed consent forms and completion of a comprehensive medical and psychiatric history, physical examination, mental status examination, and routine laboratory assessment.

The subjects will accept the drug treatment twice daily orally for 6 weeks. During the treatment follow up will occur at 8±1 days after treatment, 15±1 days after treatment, 29±2 days after treatment , 43±2 days after treatment to evaluate the safety and efficacy of the drug.

Inclusion criteria

• Outpatient or Inpatient, 18-65 years old, male or female
• Current major depressive disorder diagnosed by DSM-5, single episode(296.21, 296.22, 296.23), or recurrent episode(296.31, 296.32, 296.33)
• Montgomery-Åsberg Depression Rating Scale (MADRS) total scores in both Screening and Baseline ≥ 26
• The first item of MADRS in both Screening and Baseline ≥ 3
• CGI-S in both Screening and Baseline ≥ 4
• Able to provide written informed consent forms

Exclusion criteria

• Subjects accord with other mental disorders diagnosed by DSM-5
• Subjects who attempted to suicide, or who presently have a high risk of suicide, or with the tenth item (Suicidal ideation) of C-SSRS ≥ 3
• Baseline total scores compared with the screening period, the reduction rate of MADRS ≥ 25%
• Subjects with serious or uncontrolled cardiovascular disease, liver disease, kidney disease, blood disease, endocrine disease, respiratory disease
• Subjects with clinically significant ECG abnormal (Male QTcF ≥ 450 msec, Female QTcF ≥ 470 msec)
• Treatment with a MAOI within the 2 weeks prior to the first dose of trial medication
• Practicing 2 different treatment methods of antidepressants as recommended dose of full course (≥6 weeks)
• Subjects who have had a Vagus Nerve Stimulation (VNS) device implanted, or who have received Modified Electric Convulsive Therapy (MECT) or Transcranial Magnetic Stimulation (TMS) within 3 months of Screening, or who received light treatment, laser treatment, acupuncture and other Chinese medicine treatment, biofeedback treatment within 2 weeks of Screening
• Subjects with a history of true allergic response to more than 1 class of medications
• Subjects who participated in a clinical trial within the last 30 days