Nerve Stimulator Appears Effective in Treatment-Resistant Depression
Dec. 15, 1999 (Cleveland) -- An implantable device that is about the size of a stopwatch may put a stop to depression in patients who have failed treatment with antidepressants or shock therapy. Depression affects about 18 million Americans, but about 1 million of those people have severe treatment-resistant depression that lasts for years and is a disabling condition.
The experimental treatment works by way of a generator implanted in the chest. Wires attach the device to the vagus nerve, which runs from the neck into a brain region believed to be important for regulating mood. The generator then sends tiny electric shocks to the nerve.
The treatment, called a vagus nerve stimulator, is already FDA-approved for severe epilepsy. But the results of a multi-center study on its effect on depression were presented at the annual meeting of the American College of Neuropsychopharmacology in Acapulco earlier this week and published online Wednesday by Biological Psychiatry.
"Typically the surgery is done as an outpatient procedure that takes about an hour or two," says lead researcher A. John Rush, MD.
Rush, vice chairman for research in the department of psychiatry at the University of Texas Southwestern Medical Center in Dallas, tells WebMD that 40% of the 30 patients enrolled in the open treatment trial had at least a 50% improvement in their depression at the end of an eight-week course of treatment.
Rush says, "We have followed some of these patients for 10 months now, and we can report that those who responded during the early phase have held the response, and some patients who didn't respond during the eight-week trial responded later. So the long-term results are actually slightly more optimistic than the eight-week results that were reported in this paper."
The results are particularly compelling given the severity of depression, he says. "Twenty-one patients had major depressive disorder and nine were bipolar [formerly known as manic depressive]," he says. More than half of the patients had received ECT-- the so-called electro-shock therapy -- and all the patients failed to respond to at least two robust antidepressant medication trials.