Implanted Brain 'Pacemaker' Treats Depression
Patients Improved With Experimental Implant After Antidepressants Failed
March 2, 2005 -- A "pacemaker" implanted in the brain appears to
help severely depressed patients who don't respond to other treatments.
In a small but potentially landmark study, four out of six formerly
treatment-resistant patients got better after electrodes were implanted in a
region of their brains thought to drive depression.
Electrical stimulation of the brain using a pacemaker-like device was
introduced several years ago to help
But this is the first time so-called deep-brain stimulation has been used to
Living a Nightmare
Debbie (not her real name) is typical of the patients in the study. She
tells WebMD that her third bout of depression had lasted eight years when she
decided to have the experimental surgery a year and a half ago.
Her dark moods left her suicidal and unable to function. While
work for most people with depression, they did nothing to lift
Debbie's depression. She says the only thing did was wipe out a big part of her memory.
"I was to the point where I wasn't really planning on living this
nightmare too much longer," the 47-year-old Canadian says. "I had been
hospitalized repeatedly because I was a danger to myself. I would have tried
Deep brain stimulation targeted an area of Debbie's brain known as the
subgenual cingulated region, or Cg25. In earlier research, Helen Mayberg, MD,
showed that Cg25 is overactive in people with treatment-resistant
In collaboration with Andres Lozano, MD, who is a leading expert on
deep-brain stimulation, Mayberg and colleagues theorized that sustained
electrical jolts could normalize the targeted region and make the entire brain
behave more normally.
How It's Done
Two holes, the size of nickels, were drilled into the skulls of the patients
who remained awake. The area of the surgery was numbed with anesthetic. Using
magnetic imaging to guide them, surgeons then implanted two thin wires with
electrode contacts near the Cg25 area of the patients' brains. The loose end of
the wires were then threaded under the skin and attached to the pacemaker
device, which was implanted in the chest.
All six of the patients reported improvement soon after the surgery. Two of
the six became depressed again within six months.
The four other patients had few
after surgery, and all still have the implants. Imaging studies revealed brain
changes consistent with a return to normal Cg25 activity. These changes have
also been seen in depressed patients who respond well to drug treatment.
The findings are reported in the March 3 issue of the journal
Mayberg says the findings could represent the first step in a paradigm shift
in the thinking about depression. Drug treatments target chemical imbalances
within the brain. But the early research indicates that for some patients
successful treatment will require "rewiring" parts of the brain's
"This study tells us that this strategy has real potential … that our
first target [within the brain] looks like it was a good selection," she
says. "It may be that there are other areas of the brain that are better,
but that remains to be determined."