The year-long trial involving approximately 150 patients will record the progress of the Vagal Nerve Stimulator, a battery-operated device no bigger than a standard pacemaker. The VNS is implanted just below the collarbone and attached to the vagus nerve, electrically stimulating the areas of the brain thought to control emotions.
"The vagus nerve is the superhighway into the brain," said Charles DeBattista, assistant professor of psychiatry and behavioral sciences and director of the depression clinic at Stanford. "It leads to the limbic circuit, thought to be very important in mood regulation."
Surgery, performed with a regional anesthetic and on an outpatient basis, is completed within two hours.
Once the stimulator is in place, doctors program pulse duration and frequency of the mild electrical pulses. They control the frequency by passing a magnetic wand over the stimulator, adjusting the electrical pulses to establish an effective level.
DeBattista hopes the device will produce longer-term results than those gained from the current use of electroconvulsive therapy.
ECT is the application of an electric shock to the brain. The method of application is, however, a far cry from the barbaric image of shock treatment commonly portrayed in the movies, clinicians say.
"It is a very humane and very useful treatment," said John Barry, assistant professor of psychiatry and behavioral sciences and director of the neuropsychiatry and individual psychotherapy clinics at Stanford.
Nevertheless, the electroshock procedure is administered under a general anesthetic to prevent any limbs being broken during the seizure.
"One Flew Over the Cuckoo's Nest is an example of Hollywood doing a disservice to medicine," said Michael Cochran, who has a private psychiatry practice in Los Altos, California. "I wonder how many people were killed because of that movie -- how many people did not get ECT treatment because of it."
"ECT is only for those people who have tried many other treatments. It is a useful and common procedure," Barry added.
However, ECT is only a temporary remedy, and VNS purports to have more permanence. "Patients who receive ECT need something else to maintain the benefits of the treatment," DeBattista said.
The success of the VNS trial will be measured via standardized rating scales used to analyze depression. Results will be collated through personal interviews, questionnaires, and input from the patient's family members.
DeBattista does not see VNS as a replacement for more traditional antidepressant measures such as Prozac, monoamine oxidize inhibitors, lithium or therapy classes.
"I can imagine it being used in a small group of people who have a problem with moods being pathologically low ... people who haven't responded to a number of other antidepressant measures," DeBattista said.
"There are many drugs available for the treatment of depression; however, they are very similar to each other," said Palo Alto physician Dr. David Smith. "There are a certain percentage of people who simply do not respond to these drugs. For these people, ECT can be an effective alternative."
Smith believes that VNS could offer an alternative to drugs or psychotherapy. He believes that patients who benefit from ECT treatment could also benefit from the VNS. "We don't know if it works at all yet, who is going to respond to it, but anything that offers an alternative is good," he said.
So far the trial has not shown any significant side effects, although some patients can become hoarse during the procedure. This is caused by the proximity of the electrical stimulation to the larynx.
"There are potential side effects -- we haven't done enough research yet to see any deleterious effects on moods," DeBattista said.
The VNS was originally designed to control epilepsy. Its potential in the control of depression was discovered when patients receiving vagal nerve stimulation reported mood improvements.
"Patients would describe mood effects even if their epilepsy hadn't improved," DeBattista said. "Some patients would say their mood was much better without even knowing why."
DeBattista said many people have used VNS to regulate epilepsy for as long as a year and that no significant side effects had been reported.
Stanford's Depression Clinic is also working on a transcranial magnetic-stimulation device. This non-invasive treatment consists of a handheld coil placed on a patient's scalp. The coil produces a focused electromagnetic field stimulating the brain.