Inclusion Criteria:

• Patient is diagnosed with a major depressive episode (MDE) according to DSM-IV Diagnosis Criteria derived from the SCID.
• Patient has not had an acceptable clinical response due to failure (resistance) with at least two treatments from different treatment categories during the current MDE.
• Patient has a score ≥ 20 on the 24-item Hamilton Rating Scale of Depression.
• Patient is able to give his informed consent to participate in this study and he is able to fulfill the requirements of the study.
• Patient is a male or nonpregnant female adequately protected from conception. Females of childbearing potential must use an acceptable method of birth control.
• Convulsive therapy clinically indicated

Exclusion Criteria:

• Patient currently has a secondary diagnosis of, or signs of, delirium, dementia, amnesia, or other cognitive disorders per DSM-IV.
• Patient has had or has currently a diagnosis of non-affective psychotic disorder per DSM-IV.
• Patient has had alcohol or substance dependence within the previous 12 months or abuse within the previous six months other than nicotine dependence or abuse.
• Patient has a history or diagnosis of clinically relevant cardiac disease.
• Patient has a history or diagnosis of clinically relevant injury or disease of the central nervous system.
• Patient has magnetic material in the head.
• Patient has implanted medical devices such as cardiac pacemaker, vagus nerve stimulator, medical pumps etc.