FDA has accepted atypical antipsychotics of olanzapine and aripiprazole as the adjuvant medications for refractory major depression. But there is still no trial about atypical antipsychotics combined with antidepressant of SSRI used in fresh major depressive patients. This project aims to compare the efficacy and tolerability of sertraline with or without low-dosed aripiprazole added in fresh major depression.

This double-blind, placebo-control, fixed dose, randomized study will be conducted at a tertiary clinical setting. Patients over 18 y/o fulfilled DSM-IV criteria for major depression, having a baseline HAM-D score ≧ 14 and a HAM-D item 3 score < 3 will be recruited into the groups. The study group of patients will receive ten weeks of treatment with a combination of fix-dosed sertraline and aripiprazole. The control group will received sertraline only. The score reduction in HAM-D17, CGI, SF-36 and Brief Symptom Rating Scale (BSRS-50) will be periodically estimated as an efficacy following the use of a SSRIs or and aripiprazole.

Inclusion Criteria:

• Male or female subjects 18 to 65 years inclusive.
• Fulfilled DSM-Ⅳ criteria for major depressive disorder.
• Onset ≧2 weeks.
• Baseline score ≧14 on the HAM-D17.
• Written informed consent prior to entry into the study.

Exclusion Criteria:

• HAM-D17 item 3 score≧3.
• Life-time history of bipolar disorders, schizophrenia or schizoaffective disorder.
• Current history of panic disorder, obsessive-compulsive disorder, alcohol or substance abuse.
• Mood disorder due to general medical condition.
• Treatment with antidepressants at entry into the study before 2 weeks.
• Need for psychoactive medications other than the study drugs, except for one benzodiazepine or hypnotic given at a stable dose.
• Known intolerance or inefficacy to either drug.
• Previous lack of response to two or more antidepressants at adequate dosage.
• Subjects who have acute or unstable medical illness or organic failure.
• Pregnancy and breast-feeding.