A Phase II Study of PDC-1421 Capsule to Evaluate the Safety and Efficacy in Patients With Major Depressive Disorder

Inclusion Criteria:

1. Outpatients aged 20-65 years
2. Subjects must be able to understand and willing to sign informed consent
3. Female subjects of child-bearing potential must test negative to pregnancy and useappropriate birth control method from the beginning of study to the 15 days laterafter ending of study
4. Met criteria for MDD without psychotic features as defined by the Diagnostic andStatistical Manual of Mental Disorders, Fourth Edition Text Revision® (DSM-IV-TR) andconfirmed by use of the Mini International Neuropsychiatric Interview (MINI).
5. 17-item HAM-D (Hamilton Rating Scale for Depression) total score ≧20 and CGI (ClinicalGlobal Impression) total score ≧4

Exclusion Criteria:

1. Have a current or previous major psychiatric disorders which be defined to be per theDSM-IV-TR, including obsessive-compulsive disorder, posttraumatic stress disorder,bipolar I or II, manic or hypomanic episode, schizophrenia, major Axis II disorderswhich might compromise the study, and major depression with psychotic symptoms, mentalretardation.
2. Use of any treatment for MDD in the last 2 weeks before visit 1 (4 weeks forfluoxetine).
3. Use of psychoactive drugs within the last 2 weeks before visit 1 other than thatsubjects had insomnia who need the treatment as determined by the Investigator.
4. Subjects who were non-responsive to two or more courses of antidepressant medicationsgiven an adequate dosage for symptom treatment within four weeks, or by the judgmentof the investigator considered to have treatment resistant depression (TRD), or ahistory of electroconvulsive therapy (ECT), transcranial magnetic stimulation (TMS) orpsychosurgery within the last year.
5. Have a history of any seizure disorder.
6. Any clinically significant abnormal vital sign, ECG, laboratory values as determinedby the investigator which might interfere with the study.
7. Any organic disorder caused u medical related depression which cannot be underwell-controlled such as clinically significant in neurological, gastrointestinal,renal, hepatic, cardiovascular, respiratory, metabolic, endocrine, hematological orother major disorders
8. Have a high suicidal risk as measured by MINI.
9. Have a history of substance abuse within the past 6 months or a positive urine drugscreen for any substance of abuse at visit 1.
10. Have a history of severe allergies to more than 1 class of medication or multipleadverse drug reactions.