When doctors started using vagus nerve stimulation (VNS) to treat epilepsy, they noticed that many patients were associating VNS with a remarkable improvement in mood. In 2005, the FDA approved VNS as an option for patients with treatment-resistant depression. The procedure, which involves stimulating the vagus nerve via electrical shocks, appears to change brain wave patterns and help reduce or eliminate symptoms of depression.

How Vagus Nerve Stimulation Works

There are two vagus nerves, one on each side of the body. Both start at the base of the neck and run from the brain stem down to the chest. For VNS, a pacemaker-like device slightly bigger than a silver dollar is surgically implanted in the chest. The device—called a pulse generator—is then connected to the left vagus nerve via a wire threaded underneath the skin. The pulse generator is programmed to deliver electric current in continuous cycles. It stimulates the nerve for a set period of time and then pauses for several minutes before the next pulse is delivered.

Because the treatment is fairly new, doctors aren’t entirely sure how stimulation of the vagus nerve helps to alleviate symptoms of depression. However, many medical professionals have compared it to electroconvulsive therapy, a treatment that involves stimulating parts of the brain with electric pulses. It appears that VNS may help reset chemical imbalances in the mood centers of the brain.

Who It’s For

Vagus nerve stimulation has been used to treat depression only in the past decade. Research on its efficacy is still ongoing. It’s generally considered to be a last resort option. Doctors usually recommend that patients try different types and combinations of medication and psychotherapy—and even electroconvulsive therapy—before trying VNS. The treatment is only recommended for adults 18 and older who have treatment-resistant depression. The FDA also recommends that patients continue with other forms of therapy, such as medications, cognitive-behavioral counseling, and others, in conjunction with VNS.

Patients who are pregnant or have any other neurological conditions might not be eligible for VNS. Your doctor can help you determine whether vagus nerve stimulation is a viable treatment option. Also, many health insurance plans do not cover VNS, which can cost between $5,000 and $30,000.

Possible Side Effects and Complications

Because vagus nerve stimulation involves a major surgery to implant the pulse generator, complications may arise both during and after the surgery. Standard risks associated with the surgery include infection, pain, breathing problems, or damage to the vagus nerve. Another risk with VNS surgery is the possibility of vocal chord paralysis, which can be caused if the device moves after implantation. You may also need to stop taking certain medications several days before the procedure.

After the surgery, patients may deal with a variety of side effects, including chest pain, throat pain, and difficulty swallowing or breathing. In some patients, depression may also worsen. Also, the pulse generator might break or need to be adjusted, which would require another surgery.

What the Experts Say

Dr. Mark George, professor at the Medical University of South Carolina, suggests that VNS could provide lasting benefits for some patients. “VNS could be an effective long-term therapy to help people with chronic and recurrent depression maintain a better quality of life and a higher level of day-to-day functioning," George says.

Dr. Harold Sackeim, of the Columbia College of Physicians and Surgeons and New York State Psychiatric Institute, also believes VNS holds promise for those who haven’t succeeded with other methods. “Studies of VNS for depression thus far indicate that this therapy may be an option for patients who have not had a positive long-term response to commonly available treatments" Sackeim says.