MONDAY, Oct. 13 (HealthDay News) -- The NeuroStar TMS (Transcranial Magnetic Stimulation) Therapy system has been approved by the U.S. Food and Drug Administration for people with major depressive disorder who haven't seen satisfactory improvement from at least one prior antidepressant medication, device maker Neuronetics said in a news release.

TMS is a non-invasive therapy that involves stimulation of nerve cells in the brain that have been linked to depression. This is done by delivering MRI-strength magnetic pulses during a 40-minute outpatient procedure, in which patients do not require anesthesia or sedation, the company said. The daily treatment typically is given for four-to-six weeks.

In clinical studies involving 164 people with major depressive disorder, significant improvement was recorded for symptoms of core depression, anxiety, and other forms of psychological distress, Neuronetics said.

The most common side effect was mild-to-moderate scalp pain or discomfort at the treatment area, which declined "markedly after the first week," the company said. Fewer than 5 percent of patients stopped treatment due to adverse effects.

Initially, the therapy will only be available at a limited number of treatment centers across the United States, Neuronetics said.

More information

To learn more about depression, visit the U.S. National Institute of Mental Health.