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May 6, 2008 -- Researchers are becoming increasingly convinced that tiny electric shocks delivered deep into the brain could mean new hope for patients with severe depression and other mental illnesses.
Several small trials are suggesting direct electrical brain stimulation has the ability to relieve deep depression and obsessive compulsive disorder in some patients who get no help from drugs or talk therapy.
While the results are far from perfect, researchers believe that the treatment, known as deep brain stimulation (DBS), could be a help to some patients who otherwise might be at a dead end in their treatment.
"If we can get people out of the pit, we can get them on the road to recovery," says Helen Mayberg, MD, an Emory University neurologist who studies DBS in severely ill patients.
Deep brain stimulation involves the placement of electrodes into the brain that deliver electrical stimulation to specific brain areas. It is a treatment option for severe symptoms of Parkinson's disease and other neurological conditions.
In many patients with treatment-resistant depression or obsessive-compulsive disorder, researchers have noticed abnormal activity in an area of the brain known as Brodmann area 25.
Four out of six patients treated by Mayberg and her colleagues had relief from deep depressive symptoms several years after DBS was placed adjacent to this area.
About 50 patients have been treated in a similar way, with mixed results.
"Not all patients get better, but when patients respond, it's quite significant," Mayberg said at a forum on deep brain stimulation held at the U.S. Department of Health and Human Services in Washington. "They didn't get happy, they felt relief" from deep feelings of despair and hopelessness that often come with severe depression, she said.
Donald Malone, MD, a researcher at the Cleveland Clinic, is part of a team targeting a different brain area. Nine of 17 patients given DBS showed at least a 50% improvement in their depression symptoms after three months. Eight of 16 were still benefiting after a year.
"Certainly not all of them respond," Malone says. But in those who do, "you can see a persistent decline in their depression symptoms."
In another study, published in 2006, DBS brought significant reductions in symptoms to four of eight patients with severe obsessive-compulsive disorder. "They have moderate impairments, but they can manage much better," said Benjamin Greenberg, MD, a Brown University researcher who conducted the study.
Researchers say they need more studies to understand which brain areas play a role in severe mental disorders.
The implants may also expose patients to the risks of surgery, including bleeding and infection.
Wayne Goodman, MD, who directs the division of adult translational research at the National Institute of Mental Health, says DBS remains "a last resort" and that widespread use of the technology "would be premature."