BACKGROUND Transcranial magnetic stimulation (TMS), a noninvasive technique for stimulation of the brain, has recently been suggested to be effective for the treatment of major depression. We conducted a double-blind, placebo-controlled study to assess the efficacy of slow repetitive TMS (rTMS) in patients with major depression. METHODS Seventy patients with major depression (53 women, 17 men; mean age, 58.7 years; SD, 17.2 years) were randomly assigned to receive rTMS or sham rTMS in a double-blind design. Treatment was administered in 10 daily sessions during a 2-week period. Severity of depression was blindly assessed before, during, and after completion of the treatment protocol. RESULTS All patients completed the first week of treatment and 67 completed the entire protocol. Patients who received rTMS had a significantly greater improvement in depression scores compared with those who received sham treatment. At the end of 2 weeks, 17 of 35 patients in the rTMS group, but only 8 of 32 in the sham-treated group, had an improvement of greater than 50% in their depression ratings. CONCLUSIONS This controlled study provides evidence for the short-term efficacy of slow rTMS in patients with recurrent major depression. Additional studies will be necessary to assess the efficacy of rTMS as compared with electroconvulsive therapy as well as the long-term outcome of this treatment in major depression and possibly other psychiatric disorders.