FDA Panel Backs Implant To Counter Depression
But Questions Linger About Manufacturer Data
By Shankar Vedantam
Washington Post Staff Writer
Wednesday, June 16, 2004; Page A03
A surgical implant that stimulates the brain should get government approval to treat chronic depression, an expert panel of federal experts said yesterday -- marking the first time an implanted device has been recommended for the treatment of a psychiatric disorder.
Using a technique known as vagus nerve stimulation, the device uses electrodes implanted in the neck to activate brain regions that are believed to regulate mood.
The decision by an expert advisory panel of the Food and Drug Administration came after a day of clashing scientific opinions about whether the data submitted by the manufacturer were adequate for approval. Proponents of the device prevailed, citing the desperate need of patients with chronic depression that does not respond to existing treatments.
"We lost four of these individuals in the last 2 1/2 hours," said A. John Rush, a psychiatrist at the University of Texas Southwestern Medical Center at Dallas, basing that figure on the high suicide rate among patients with resistant depression.
The verdict by the advisory panel came after FDA scientists and some panel members argued the data presented by the manufacturer to show the device works were not convincing.
The agency is not required to follow the guidance of its advisory committee but usually does.
The device has been used in the United States since 1997 to control epileptic seizures. The manufacturer, Cyberonics Inc. of Houston, hopes to expand its market: Fifteen to 25 percent of the 19 million Americans with depression may not respond to available treatments, Rush said.
The implant involves connecting a wire to the left vagus nerve in the side of the neck; a battery is implanted high in the left chest or under the armpit, and the amount of current can be regulated externally. Typically, the implant sends a 30-second pulse of current followed by a five-minute pause, 24 hours a day.
Karmen McGuffee of Garland, Tex., told the panel she had tried virtually every antidepressant drug on the market before getting the device. Improvement came within weeks, she said.
"My mother said she wasn't looking into the eyes of a dead person anymore," she said. When people asked why she was willing to get an implant, she replied, "I had nothing to lose."
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