Patient description: A 46-year-old Asian woman with MDD complains of persistent feelings of sadness and loss of interest in daily activities. She states that her mood is still depressed most of the days. She complains of loss of energy and feelings of worthlessness nearly every day. She is on anti-depressants for the past 6 months, but the symptoms are still present. She does not drink alcohol or smoke. She used to exercise every day for at least 30 min., but she doesn't have enough energy to do so for the past 3 weeks. She also has some digestive issues recently. She is married and has 4 children. She is menopausal. Her husband was diagnosed with colon cancer a year ago and is undergoing chemotherapy. Her past medical history is unremarkable. Her family history is negative for any psychologic problems. Her HAM-D score is 20.

Clinical trial eligibility criteria: eligible ages (years): 18.0-65.0,  Depressive Disorder, Major Major Depressive Disorder (MDD) Male and female subjects between the ages of 18 years with a psychiatric diagnosis of a MDE associated with MDD according to DSM-IV-TR (296.2/296.3) whose symptoms are considered mild to moderate and have not been taking antidepressant medication at the time of screening and for at least 4 weeks prior to randomisation If female, the subject is eligible to enter and participate in this study if she is not lactating and is of: 1. Non-childbearing potential (i.e., physiologically incapable of becoming pregnant, including any female who is post-menopausal [defined as one year without menses for women >45 years of age]); is surgically sterile [via hysterectomy and/or removal of the ovaries] or, 2. Child-bearing potential, has a negative pregnancy test at both screen and baseline (prior to investigational product administration), and agrees to acceptable methods of contraception Body weight ≥ 50 kg and body mass index (BMI) between 18.5 0 kg/m2 inclusive Capable of giving informed consent and can comply with the study requirements and timetable Subjects have a HAM-D17 score > 18 and <25 at screening and baseline The subject must be able to read, comprehend and record information Non-smoker or light (< 10 cigarettes per day) smoker Agree to abstain from alcohol for 24 hours prior to the start of dosing until collection of the final pharmacokinetic sample  Subjects whose symptoms of the MDE are better accounted for by another diagnosis As a result of any of the medical interview, physical examination or screening investigations the physician responsible considers the subject unfit for the study The subject has a history of a drug reaction or other allergy which in the opinion of the physician responsible contraindicates their participation in the study The subject is currently participating or has participated in a clinical trial with a new chemical entity or any investigational drug during the previous 2 months. In addition, the subject has not participated in clinical trials with more than 3 new chemical entities in the past 12 months The subject has a screening ECG with parameters outside ranges defined in the protocol The subject has a pulse rate <45 or >100 bpm and/or a systolic blood pressure >150 and/or <90 and/or a diastolic blood pressure >90 and <50 History of long QT syndrome (personal or family) or other cardiac conduction disorder, or other clinically significant cardiac disease The subject has any liver function test (LFT) elevated >1.5 times above the reference range at pre-study screening that remain elevated with a repeat LFT Any other clinically significant laboratory abnormality Use of prescription or non-prescription drugs, including vitamins, herbal and dietary supplements (including St John'sWort) within 7 days (or 14 days if the drug is a potential enzyme inducer) or 5 half-lives (whichever is longer) prior to the first dose of study medication, unless in the opinion of the Investigator and sponsor the medication will not interfere with the study procedures or compromise subject safety