Repetitive transcranial magnetic stimulation (rTMS) is a new technique for activating the brain noninvasively through the scalp and skull. It has proven effective in producing localized effects on brain function and has opened many areas of human brain function to direct investigation. Preliminary data also suggest potential therapeutic applications in neuropsychiatric illness. We plan to further investigate the possible therapeutic use of rTMS in depression under conditions of high frequency (20 Hz), low (1Hz) frequency, and sham and to also examine possible cognitive or endocrine effects. Among the priorities of this protocol will be to further evaluate the risks of the technique.