More than 18 million
Americans are afflicted with bouts of clinical depression each year, and
for most of them, antidepressants and/or psychotherapy are effective treatments,
but the drugs don't work for everyone.
Between 10 percent and 20 percent
of people with depression do not respond to drugs, psychotherapy or even
electroshock treatments. For at least some of them, there may be
new hope in the form of a small electrical-impulse generator developed
to stop or reduce seizures in people with epilepsy who were not helped
by other treatments.
When researchers were testing
the device in epilepsy patients, they discovered an unexpected benefit.
Whether or not the device helped the seizures, many of the patients who
were clinically depressed got better.
A pilot study done at four university
medical centers in depressed patients found the device was effective in
close to half of those who had not been helped by any other treatment.
"It's not like a magic antibiotic,
but people who have failed to respond to antidepressants or electroshock
therapy - about 40 to 50 percent of them responded," said Dr. Paul Goodnick,
a behavioral scientist and professor of clinical psychiatry at the University
of Miami School of Medicine.
The device developed by Cyberonics
Inc. of Houston is a little bigger than a quarter. It contains a tiny batter
that will produce electrical impulses for up to a dozen years. Wires
connect the device to the left vagus nerve, one of a pair of nerves that
run throughout the body with 13 main branches, four of them in the brain.
The nerves are essential for many of the body's functions including swallowing,
speech, sleep, appetite and emotions.
A surgeon implants the device
below the collarbone during a procedure that takes about one hour and can
be done with local anesthetic, Goodnick said. The device is activated
and adjusted later with a special programming wand hooked up to a computer.