Psychotherapy and antidepressants treat only about one-third of patients who suffer depression, but a magnetic therapy is promising, a U.S. researcher said. Dr. Murali Rao of Loyola University Medical Center in Maywood, Ill., said nearly 300 U.S. centers offer the treatment, called transcranial magnetic stimulation, a treatment that sends short pulses of magnetic fields to the brain. At Loyola, about two-thirds of Rao\'s transcranial magnetic stimulation patients reported their depression has significantly lessened or gone away completely. In 2009, the U.S. Food and Drug Administration approved transcranial magnetic stimulation for patients who have major depression and have failed to experience improvement from at least one antidepressant. One transcranial magnetic stimulation system, NeuroStar, made by Neuronetics, has the patient recline in a comfortable padded chair. A magnetic coil is placed next to the left side of the head that sends short pulses of magnetic fields to the surface of the brain, producing currents that stimulate brain cells, Rao said. The currents, in turn, affect mood-regulatory circuits deeper in the brain. The resulting changes in the brain appear to be beneficial to patients who suffer depression, Rao said. Each treatment lasts 35 to 40 minutes. Patients typically undergo three treatments per week for four-to-six weeks, Rao explained. The treatments do not require anesthesia or sedation, and a patient can immediately resume normal activities, including driving.