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.

Transcranial magnetic stimulation is a noninvasive technique that can influence specific areas of the brain and has very few side effects.Several factors characterize repetitive transcranial magnetic stimulation (rTMS) as a strategic aid in the treatment of depression.Depression is a chronic illness and generally requires life-long treatment. However, up to current days there have been no studies evaluating the effects of rTMS in the maintenance treatment of depression. This is a randomized, double-blind, placebo-controlled, parallel-group, multicenter study to evaluate the efficacy of rTMS, as monotherapy, relative to placebo in delaying the time to relapse in patients with depression. Patients with acute symptoms of depression will be enrolled. The study will consist of 4 periods: an up to 7 days screening/tolerability period, a 6-week open-label flexible dose lead-in period, a 6-week open-label fixed dose stabilization period, and a 12 months double-blind relapse prevention period. The study will consist of 4 phases: a screening/tolerability phase of up to 7 days; an open-label, flexible-dose lead-in phase of 8 weeks; an open-label, fixed-dose stabilization phase of 6 weeks; and a single-blind relapse prevention phase of 12 months. During the open-label phase, all patients will be treated with venlafaxine. Remitterswith Hamilton Rating Scale for Depression [HAM-D17] score ≤ 7will be eligible to enter the single-blind phase and will be randomly assigned to one of three groups: group 1 on active rTMS and venlafaxine; group 2 on sham rTMS and venlafaxine; group 3 on venlafaxine alone. Efficacy will be evaluated during the study using relapse assessment (time between subject randomization to treatment and the first occurrence of relapse). Secondary outcome measures will include: symptom changes, measured by the Hamilton Rating Scale for Depression [HAM-D17]; illness severity changes, measured by the Clinical Global Impression of Severity for Depression (CGI-S-DEP); and changes in subject functioning, assessed with the Personal and Social Performance Scale. Safety will be assessed throughout the study by monitoring of adverse events, clinical laboratory tests, electrocardiography, and measurements of vital signs (temperature, pulse and blood pressure) and weight. Suicidality will be assessed by the Columbia Suicide Severity Rating Scale (C-SSRS). A 10 milliliter pharmacogenomic blood sample (sample for DNA research) will be collected from patients who give separate written informed consent for this part of the study.

Inclusion Criteria:

• DSM-IV diagnosis of depression
• Experiencing an acute exacerbation of depression symptoms
• Baseline score of at least 14 points on the Hamilton Depression rating Scale-17 items
• Healthy based on physical examinations, electrocardiogram (ECG), laboratory tests, medical history, and vital signs measurements

Exclusion Criteria:

• Comprised ferromagnetic metallic implants
• Pacemakers
• Previous neurosurgery
• History of seizures
• Major head trauma
• Alcoholism
• Drug addiction
• Any psychiatric or neurological disorder other than depression and anxiety
• Psychotic depression
• Suicidal propensities