University Of Pittsburgh Doctors Among Nation’s First To Test Electronic Device To Ease Depression
PITTSBURGH, October 27, 2000 — Researchers at the University of Pittsburgh Medical Center’s (UPMC) Western Psychiatric Institute and Clinic are among the first in the nation to study whether a small implanted electronic device is a safe and effective treatment for patients with treatment-resistant depression (TRD).
If successful, the new treatment may become a unique and effective alternative to electroconvulsive therapy (ECT), now the most common treatment for TRD.
Like a pacemaker for the brain, the NeuroCybernetics Prosthesis (NCP) helps regulate nerve impulses by sending intermittent mild pulses of electricity directly to the vagus nerve. The NCP is surgically implanted in a patient’s left upper chest and is connected to the vagus nerve in the neck by way of a flexible lead. Signals from the NCP travel through the lead, up the vagus nerve, and into the brain.
As one of 20 centers in the United States that will conduct the double-blind study, UPMC will implant the device in up to 30 patients. Each patient will be evaluated for approximately 12 weeks after getting the device. At the end of the study period the researchers will issue their findings in the form of a recommendation to the U.S. Food and Drug Administration on whether or not to support approving the use of the NCP for TRD.
Depression is more than just the blues. It is a serious psychiatric disorder that causes problems in relationships at home and at work. The disease affects about 5 percent of the population of the United States at any given time. Women are twice as likely to suffer depression. The economic cost of depression is more than $40 billion a year.
Numerous antidepressant drugs are available to treat the disease, and most people respond to a combination of drugs and talk therapy. However, approximately 30 percent of the estimated 1.5 percent of the general population with severe, recurrent episodes of depression has a form that is resistant to conventional treatment.
The most commonly followed course of treatment for TRD is ECT, which, while effective, involves the repeated use of general anesthesia and requires multiple treatments over a period of several weeks or even months. ECT may cost from $8,000 to $20,000 per patient per year and carries the risk of short-term and possibly long-term memory deficits.
Vagus nerve stimulation with the NCP system has been used safely in Europe for the treatment of epileptic seizures since 1994 and in the U.S. since 1997. The idea of using the NCP for the treatment of depression came about because doctors who used it to treat patients with epilepsy noticed that those patients’ moods improved markedly. A recent pilot study showed that the NCP system seemed to help nearly 50 percent of patients who had TRD.
"A new solution to treatment-resistant depression is very exciting," said Robert H. Howland, M.D., associate professor of psychiatry at the University of Pittsburgh School of Medicine and principal investigator of the Pittsburgh study. "Outside of electroconvulsive therapy, there is almost nothing a doctor can do for someone with TRD. This is a simple device that, if effective, will dramatically improve the quality of life for people with TRD."
The NCP pulse generator is about the size and shape of a large pocket watch and is implanted under the skin on the upper left side of the patient’s chest. The bipolar lead is a 16-inch long flexible, insulated tube that houses the electrodes, and is attached to the vagus nerve on the left side of the neck. The lead then conducts the electrical signals from the pulse generator to the vagus nerve. The signals are then carried by the nerve to the brain.
The procedure to implant the pulse generator and bipolar lead requires the patient to undergo general anesthesia just once, and generally takes about 45 minutes to two hours. The patient can go home the same day. Adjustments to the electrical stimulus can be made from outside the body by way of a programming wand and computer software. The wand is simply passed over the pulse generator outside the body and new settings are programmed.
The vagus nerve is used for several reasons. There are very few pain fibers in the nerve, which means that treatment with the NCP is relatively painless. And, the vagus nerve is one of the major nerves leading directly from the brain through the neck and throughout the upper body. In an adult, the nerve averages 22 inches in length. It serves as one of the primary communication links between the organs of the body and the brain, and more than 80 percent of the electrical signals applied to the vagus nerve reach the brain. Vagus nerve stimulation appears to directly affect those parts of the brain involved in the regulation of moods.
Because the initial 12-week study is double-blind, the NCP will be implanted in all participants, but activated in only half, at random. Neither patients nor researchers will know which devices are turned on. At the end of the 12-week study, however, all patients will have the NCP activated and either may continue in long-term treatment or have it removed.
This study is no longer seeking participants.