Transcranial Magnetic Stimulation (TMS): is a noninvasive procedure that uses magnetic fields to stimulate nerve cells in the brain to improve symptoms of depression. This procedure is typically used when other depression treatments haven't been effective. During a session, an electromagnetic coil is placed against your scalp near your forehead. The electromagnet coil painlessly delivers a magnetic pulse that stimulates nerve cells in the region of your brain involved in mood control and depression. It's thought to activate regions of the brain that have decreased activity in depression.