Patient description: The patient is a 47-year-old Asian woman complaining of persistent feelings of sadness. She lost interest in activities she used to enjoy. She states that her mood is mostly depressed for the past 3 weeks. She also lost her appetite , which led to about 5kg weight loss. She complains of loss of energy and feelings of worthlessness nearly every day. She is not using any drugs and she does not smoke. She doesn't drink alcohol. 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 recently diagnosed with colon cancer and he is starting his chemotherapy. There is nothing remarkable in her past medical history and her drug history is only positive for Vit D3 1000 units daily. Her family history is negative for any psychologic problems. Her HAM-D score is 20.

Clinical trial eligibility criteria: eligible ages (years): 18.0-999.0,  Depressive Disorder Healthy as determined by a responsible physician, based on a medical evaluation including medical and psychiatric history (including family history), full physical examination, laboratory tests and cardiac monitoring Male or female between 18 and 45 years of age (young healthy population) and >65 years old (elderly population) A female subject is eligible to participate if she is of Non-childbearing potential defined as pre-menopausal females with a documented tubal ligation or hysterectomy; or postmenopausal defined as 12 months of spontaneous amenorrhea Child-bearing potential and agrees to use of specific contraception methods. Use of oral contraception is permitted BMI within the range 19 kg/m2 (inclusive) Capable of giving written informed consent, which includes compliance with the requirements and restrictions listed in the consent form QTcB or QTcF < 450 msec; or QTc < 480 msec in subjects with Bundle Branch Block Able to swallow and retain oral medication  A subject will not be eligible for in this study if any of the following apply Evidence or history of clinically significant hematological, renal, endocrine, pulmonary, gastrointestinal, cardiovascular or other heart disease, glaucoma, diabetes, hepatic, neurologic (e.g. including but not limited to seizures, stroke, cerebrovascular disease or other brain conditions), or allergic disease (except for untreated, asymptomatic, seasonal allergies at time of dosing) Psychiatric illness currently or within the past year, or any lifetime history of bipolar disorder, major depressive disorder, anxiety disorder, schizophrenia or other psychotic disorder, or substance abuse or dependence (except past history of nicotine abuse/dependence) Subjects who, in the investigator's judgment, pose a suicidal or homicidal risk, or any subject with a history of suicidal or homicidal attempts or behaviour The subject has a positive pre-study drug/alcohol screen. A minimum list of drugs that will be screened for amphetamines, barbiturates, cocaine, opiates, cannabinoids and benzodiazepines A positive pre-study Hepatitis B surface antigen or positive Hepatitis C antibody result within 3 months of screening (with the exception of phase I hepatic impairment studies, oncology studies, hepatitis, hepatic fibrosis, or HIV studies) A positive test for HIV antibody History of regular alcohol consumption within 6 months of the study defined as an average weekly intake of greater than 21 units or an average daily intake of greater than 3 units (males), or defined as an average weekly intake of greater than 14 units or an average daily intake of greater than 2 units (females). One unit is equivalent to a half-pint (220mL) of beer or 1 (25ml) measure of spirits or 1 glass (125ml) of wine The subject has participated in a clinical trial and has received an investigational product within the following time period prior to the first dosing day in the current study: 60 days i.e. 5 half-lives