The aim of this study was to investigate the relationship between antidepresant therapy response and age, number of epizodes, duration of epizodes, and family history of psychiatric disorder. Sertraline, being and antidepresant drug, was administered using an elastic dose strategy, to a total of 609 patients (378 females, 231 males) diagnosed as depression according to DSM-III-R. The patients were allocated in to 4 subgroups according to their ages, 2 subgroups according to number of episodes, 5 subgroups according to the duration of episodes and 2 subgroups according to the family history of psychiatric disorder. Severity of depression was assessed by using the Hamilton Depression Scale (HDS), change in HDS score, Clinical Global Impressin Scale (CGIS) and Global Recovery Scale (GRS). Total response of the whole group was evaluated as well as the comparisons between all of the groups. As a result, the therapeutic response of the study group was found to be 87.1 % according to CGIS, 91.4 % according to GRS. Although response to antidepressant therapy was patients with single epizode and no family history of psychiatric disorder when compaired with the patients with recurrent episodes and positive family history of psychiatric disorder (p<0.01).