- Background: deep transcranial magnetic stimulation (dtMs) is effective in treatment of Major depressive disorder (Mdd), and in re-treatment in case of relapse. Our study evaluates the long-term durability of dtMs in Mdd. Method: seventeen patients that responded to dtMs treatment evaluated. Follow-up period was 9.3 months. Patients were considered as relapsed if: HdRs (Hamilton depression Rating scale) score was 16 points or more, in case of change in antidepressants, hospitalization due to exacerbation, referral to eC t. Results: six months after last treatment three patients relapsed (17.6%). during the follow-up of 9.3 months, nine relapsed. Relapse rate was 5.6 per 100 person-months. Patients continued to improve in HdRs following the treatment. We have found number of treatment sessions, stimulation, age, age of depressive disorder onset, length of depressive episode prior to the first treatment, as well as number of depressive episodes to have no predictive value regarding propensity to relapse in these patients.