Major Depressive Disorder (MDD) is associated with functional impairment and disability, and results in a significant burden on the affected individual, his or her family, and society in general. Psychopharmacological therapy has been shown to be effective, but may be accompanied by significant side effects. The investigators propose an alternative model, based on the relationship between symptoms, brain metabolism, and neural activity as recorded with electroencephalography (EEG). Subjects with MDD often have decreased brain metabolism, accompanied by increased EEG activity in the alpha band. The investigators hypothesis is that a gentle, non-significant risk, sinusoidal magnetic field above the subject's scalp, which oscillates at precisely his or her Intrinsic Alpha Frequency (IAF) can take advantage of this relationship to reduce symptoms without the significant side effects associated with pharmaceuticals. The investigators propose a 4-week, sham controlled, randomized, double-blind multi-center feasibility study to determine the efficacy of synchronized low energy magnetic fields delivered at the subject's IAF to treat MDD. Treatment will be given concomitant to the subject's existing medication, and will occur 5 days per week at the clinical site. Target enrollment is 45 adult subjects diagnosed with MDD.
