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): 20.0-999.0,  Depressive Disorder <at the start of placebo run-in phase> Only the patients who meet all of the following conditions at Week -1 (at the start of placebo run-in phase) will be enrolled in this study. The hospitalization status will be no object. and Gender: No object Target disease: Patients diagnosed as having one of the following depressive disorders based on DSM-IV-TR classification in conjunction with M.I.N.I. (The Mini International Neuropsychiatric Interview, Japanese version 5.0.0. [2003]) and showing currently a symptom of depression or depressed sate Major depressive disorder, single episode (296.2) (excluding those accompanied by comorbid psychiatric disorders) Major depressive disorder, recurrent (296.3) (excluding those accompanied by comorbid psychiatric disorders) Age: >= 20 years (at the time of obtaining consent) Consent: Patients from whom written consent to participate in this study can be obtained Gender Female patients of childbearing potential can be enrolled. But, such patients who can be enrolled are limited to only those who are negative in the pregnancy test performed at the start of the placebo run-in phase and who agree to receive a pregnancy test at the time point defined in the study period and surely perform any of the contraceptive methods Male subjects must abstain from (or use a condom during) sexual intercourse with a pregnant or lactating female. Male subjects must abstain from or use a condom plus spermicidal agent (foam/gel/film/cream/suppository) during sexual intercourse with a female of child-bearing potential Patients whose HAM-D (17 items) total score is >= 20 points  <at the start of placebo run-in phase> The patients who are meeting any of the following conditions at Week -1 (at the start of placebo run-in phase) must not be enrolled in this study Patients whose primary diagnosis is a disorder classified to Axis I other than major depressive disorder in DSM-IV-TR classification (dysthymic disorder, eating disorder, specific phobia (monophobia), posttraumatic stress disorder, obsessive-compulsive disorder, panic disorder, etc.) Patients with a current DSM-IV-TR Axis II diagnosis that suggested non-responsiveness to pharmacotherapy or non compliance with the protocol (e.g., antisocial or borderline personality disorder) Patients with a history or complication of another (non-MDD) mental disorder (schizophrenia, etc.) Patients with a history or complication of manic episodes Patients diagnosed as having an attentional deficit disorder or hyperactivity disorder Patients diagnosed as having a pervasive development disorder or mental retardation Patients diagnosed as abusing or dependent on alcohol or drug within one year before the Week -1 visit Patients who have undergone electroconvulsive therapy within one year before the Week -1 visit for the treatment of the current episode