MONDAY, April 28 (HealthDay News) -- For those with the most severe depression, a novel therapy may offer new hope.

The treatment is deep brain stimulation (DBS), which is used for some people with Parkinson's disease, and researchers found that it cut depression symptoms by 50 percent for about half of those treated.

"This is a new therapy for patients with severe, intractable depression. There's a lot of promise for this approach," said study author Dr. Ali Rezai, director of the Center for Neurological Restoration at the Cleveland Clinic in Ohio.

Deep brain stimulation requires minimally invasive surgery to place electrodes into specific parts of the brain that are believed to be malfunctioning. Once in place, the electrodes emit tiny, adjustable, electrical pulses that block dysfunctional activity in the brain. It's been used for about 20 years in the treatment of Parkinson's disease. Rezai added that the current group working on DBS and depression, which includes researchers from Brown University and Massachusetts General Hospital as well, has also had success using DBS to treat obsessive-compulsive disorder.

Severe depression occurs in about 10 percent to 20 percent of depression cases, according to Rezai. Antidepressants, and even electroconvulsive (ECT) therapy, often fail to bring about improvement in depressive symptoms for those with this severe form, leaving them at an increased risk of suicide. The suicide rate in people with major depression may be as high as 15 percent, according to the researchers.

In the current study, 15 people suffering from severe depression for at least five years who weren't helped by other forms of treatment received DBS implants. Six months later, 47.1 percent had at least a 50 percent reduction in their depressive symptoms, based on a commonly used depression scale. At one year, that number was 50 percent.

Even patients who didn't meet the 50 percent reduction criteria used as an endpoint in this study still experienced some symptom reduction, according to Rezai, who added that all of the participants said they would undergo DBS again.

The procedure was well-tolerated, and just one patient had a brief seizure in this study.

"This is not for everyday depression, but for those who have failed everything else, hope is on the way," said Dr. Kathryn Holloway, a professor of neurosurgery at the Virginia Commonwealth University Medical Center in Richmond. "There are new treatments being developed that are having success where no medication has," she noted. Other treatments that have shown promise include vagal nerve stimulation and transcranial magnetic stimulation. The problem, she said, is that many insurers won't cover these procedures for depression.

Rezai was expected to present the findings April 29 at the American Association of Neurological Surgeons annual meeting, in Chicago. He said that his DBS group is now conducting a larger, controlled study.

Another depression study being presented Monday at the meeting found that people on medications for clinical depression who underwent surgery for a malignant brain tumor, called an astrocytoma, had an increased risk of death after the surgery.

Depression prior to surgery upped the odds of death after surgery by about 40 percent, according to the Johns Hopkins School of Medicine study. At 12 months after surgery, just 15 percent of those who were depressed before their operation were alive, compared to 41 percent of those who weren't depressed. At 20 months, none of the depressed patients were still alive, yet 21 percent of the non-depressed were still alive. The authors concluded that effectively treating depression before surgery might help improve outcomes.

More information

To learn more about deep brain stimulation (DBS), visit the American Association of Neurological Surgeons.

SOURCES: Ali Rezai, M.D., the Jane and Lee Seidman Chair in Neurosurgery, and director, Center for Neurological Restoration, Cleveland Clinic, Ohio; Kathryn Holloway, M.D., professor, department of neurosurgery, Virginia Commonwealth University Medical Center, Richmond, Va.; April 29, 2008, presentation, American Association of Neurological Surgeons annual meeting, Chicago

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