 This double-blind, placebo-control, fixed dose, randomized study will be conducted at a tertiary clinical setting. Patients over 18 yo 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. 