The Vagus Nerve Stimulation (VNS) System is approved for adult patients with long-term or recurrent major depression that has not responded properly to four or more antidepressant treatments.
According to WebMD, the VNS is a stopwatch-sized device that's surgically implanted in the upper chest. Tiny wires attach the device to the vagus nerve, which runs from the neck to the brain. The electrical stimulation is thought to alter the chemical transmitters that carry messages between nerve cells involved in regulating mood.
The device is made by Cyberonics.
The company reports more than 32,000 patients worldwide have used the VNS Therapy System.
The device was previously submitted for approval in August 2004 for depression, but the FDA rejected it at that time, asking for additional information.
Cyberonics says the most common side effects from VNS therapy include hoarseness, a prickling feeling on the skin, and increased coughing - diminishing over time.
