TUESDAY, April 25, 2006 (HealthDay News) -- Inserting two tiny "pacemakers" into the base of the brain of people suffering from major depression improved symptoms of the sometimes intractable disease, a small study found.
The treatment, called deep brain stimulation, utilizes tiny pulses of electrical stimulation to block abnormal activity in the brain, the researchers said.
"It was interesting and impressive to see how their lives changed over time," said study author Dr. Ali R. Rezai, head of Stereotactic and Functional Neurosurgery at the Cleveland Clinic Foundation. "They went from being withdrawn and not interacting to going back to work, and showed marked improvement in self care and social function. They are living their lives much more fully than they were when they were stuck in the grip of depression."
The researchers inserted pairs of the tiny electrodes into six patients who had failed to benefit from other forms of treatment, such as medication, psychotherapy, and electroconvulsive therapy. Over the course of a year, two-thirds of the patients showed marked improvement, said the researchers, from the Cleveland Clinic and Brown University's Butler Hospital.
A similar successful study was reported last year in the journal Neuron.
Rezai was to present the findings Tuesday at the American Association of Neurological Surgeons annual meeting, in San Francisco.
The six patients -- four women and two men, with an average age of 48 -- had bilateral deep-brain stimulation leads implanted in a part of the brain called the ventral anterior internal capsule. They underwent standardized and detailed psychiatric, quality-of-life, and neuropsychological tests on a regular schedule, the researchers said.
Six months after surgery, four of the six patients showed a 50 percent or greater improvement on the Montgomery-Asberg Depression Rating Scale. Measurements of quality-of-life improved, too, the researchers said.
Deep brain stimulation surgery has proved successful in the past for patients suffering from obsessive-compulsive disorder, epilepsy and Parkinson's disease, Rezai said.
Exactly why the treatment works is not yet understood, but it appears to help the brain resume normal electrical and chemical function.
The surgery is reversible, Rezai said, and the electrodes can be adjusted without further invading the brain. It is performed under a local anesthetic, and, in some cases, the change in the patients "could be seen almost instantly," he said.
"As we were testing the pacemakers [during the surgery], we could see immediate change in their moods," he said, adding that people who hadn't smiled in years, smiled.
"But," he cautioned, "this is for people with no other hope. These poor patients had failed everything. I am encouraged by the results, but we need to do more long-term and larger studies."
Dr. Michael Blumenfield, Sidney E. Frank distinguished professor of psychiatry and behavioral sciences at New York Medical College in Valhalla, N.Y., said he had not seen the study. But he said that he's skeptical of invasive treatments that can potentially do more harm than good, particularly when there are effective treatments already available.
While it's good to look for more and better ways to treat major depression, too often it is improperly diagnosed, he said.
"Sometimes one thinks one has a simple depression when it is a bipolar depression that needs a mood stabilizer," Blumenfield said. "Sometimes the underlying problem is substance abuse, and sometimes when one has resistant depression, the issue has psychological roots, and there is a need for psychotherapy."
All of the patients in the study were resistant to other treatments, including medication, psychotherapy and electroconvulsive therapy, Rezai said.
An estimated 9.5 percent of the adult U.S. population -- about 18.8 million people -- suffers from a depressive disorder each year. The pricetag to the American workplace alone is as much as $40 billion annually. And depression is a global health-care concern, with the World Health Organization rating major depression the top cause of disability worldwide, the researchers said.
The National Alliance on Mental Illness has more on major depression.