With a growing number of elderly persons, geriatric depression - associated with important morbidity and mortality- is becoming a significant health problem. Given the risk of polypharmacy and increased side effects, alternative non pharmaceutical treatments such as repetitive transcranial magnetic stimulation (rTMS) may be a solution. Given recent positive results with accelerated rTMS in the elderly depressed, it is of interrest to continue to develop promising non-invasive treatment stimulations. The FDA approved deep brain TMS (dTMS) technique may be a promising option, targeting the brain underneath the neocortex with potentially better response and remission rates. Therefore, in a sham-controlled cross-over fashion, the investigators will treat 44 geriatric depressed patients with accelerated dTMS (5 sessions/day over 4 days only), and evaluate clinical efficacy and safety. Because new introduced rTMS paradigms should be rigorously neurobiologically examined before applying them on a regular basis, this research will include multimodal brain imaging techniques to elucidate the working mechanisms of this application in order to optimize treatment for such populations.

An initially double-blind sham-controlled cross-over study in geriatric depressed patients to investigate whether accelerated (a)dTMS is a safe and effective clinical option for this cohort. After the first week evaluations and MRI, there will be an open label phase in which patients who did receive active treatment in the first week will not receive any further rTMS sessions, those patients who had received sham however will get their active treatment in the second week. The independent researcher will use the treatment allocation list to inform the investigators if an active treatment faze is needed in the second week.