Efficacy of Repetitive Transcranial Magnetic Stimulation in the Prevention of Relapse of Depression

The purpose of this study is to evaluate the efficacy of repetitive transcranial magnetic stimulation in the prevention of relapse of the symptoms of depression. Primary Outcome Measures:Time between subject randomization to treatment and the first occurrence of a relapse during the Relapse Prevention Period. Secondary Outcome Measures: Symptom change as measured by Hamilton Depression Rating Scale (HDRS); Illness severity change as measured by Clinical Global Impression of Severity for depression(CGI-S-DEP); Change in subject functioning using the Personal and Social Performance Scale.