JOANNE SILBERNER: I'm Joanne Silberner. Tomorrow, the Food and Drug Administration will take up the question of whether TMS lifts depression. They'll also examine new evidence on a therapy they've already approved, vagus nerve stimulation. VNS uses an electric current to stimulate the brain. Both of these treatments are targeted at the small number of patients who don't respond to anti-depressant drugs or psychotherapy.
Psychiatrists are divided about these two therapies. Paul Holtzheimer of Emory University has done some research paid for by a TMS manufacturer, and he took part in a government-funded evaluation of a TMS system. In that study, 68 patients sat under the electromagnet. Everyone thought they were getting the treatment, but only half did. For some, the magnetic field was aimed away from the head.
Dr. PAUL HOLTZHEIMER (Professor, Emory University): And we showed a 30 percent difference versus a 6 percent difference in the sham group. And that was, we felt, clinically significant. And when we talked to the patients, for those patients that got better, that was a very meaningful change. And that change was in a group of patients that we didn't otherwise expect to get better with just another medication.
SILBERNER: Holtzheimer has also had patients who opted for the other approach being considered by the FDA: vagus nerve stimulation.
Dr. HOLTZHEIMER: The small wire attached to the vagus nerve - which is a nerve that comes out of the brainstem - and that electrode around the nerve, delivers stimulation to that nerve, which actually feeds back into the brain. So it's a form of brain stimulation from a remote location from the vagus nerve.
SILBERNER: It requires surgery to implant the battery and wire. When the FDA approved vagus nerve stimulation for depression in 2005, it was a controversial move. The initial data submitted by the company didn't show any clear evidence that there were any benefits after three months of treatment. At a time, FDA staffers advise against approval. Then the company did more testing, this time without comparing to a placebo or another treatment, and the FDA said yes.
Still, most insurers - including Medicare - aren't paying for it. Tomorrow, the FDA will look at how the procedure is working in the real world.
Washington, D.C. psychiatrist Wayne Blackmon is among a group of psychiatrist who think it should never have been approved.
Dr. WAYNE BLACKMON (Psychiatrist): Although there is some promise that appears to be held out by some studies, the studies backing the use of VNS for severe depression really are inadequate, and it really is not ready for primetime.
SILBERNER: Blackmon doesn't agree with psychiatrists who say that given the real risk of suicide among these patients, the FDA approval was justified.
Dr. BLACKMON: VNS is an invasive procedure. So you expose people to risks without any clear-cut benefit beyond placebo.
SILBERNER: Blackmon is open to the magnetic stimulation therapy. He points out that TMS doesn't require surgery, has no significant side effects, and is cheaper. Tomorrow, FDA advisers will weigh in on both these therapies. Meanwhile, a third therapy that involves putting electrodes deep inside the brain, called deep brain stimulation, is still in testing.
Joanne Silberner, NPR News, Washington.
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