|Deep Brain Stimulation for Depression|
Deep brain stimulation, an experimental and invasive treatment that involves stimulating the brain with electrical signals, may help treat otherwise difficult to cure depression, a new study reports.
Depression is an illness that involves the body, mood and thoughts. Imbalances in three brain chemicals, serotonin, norepinephrine and dopamine, are linked to depression. Unlike normal emotional experiences of sadness, loss or passing mood states, depressive disorders are persistent and can significantly interfere with an individual's thoughts, behavior, mood, activity and physical health.
Depressive disorders affect approximately 18.8 million American adults or about 9.5 percent of the U.S. population age 18 and older in a given year. Among all medical illnesses, major depression is the leading cause of disability in the United States and many other developed countries. Without treatment, symptoms can last for weeks, months or years. Appropriate treatment, however, can help most people who suffer from depression.
Researchers from the University of Toronto, Toronto, Canada, explained that an early report in six patients suggested that deep brain stimulation of the subcallosal cingulate gyrus (part of the brain) may provide benefit in treatment-resistant depression.
In the study, 20 patients with treatment-resistant depression underwent serial assessments before and after the deep brain stimulation. The researchers analyzed the percentage of patients who achieved a response or remission after surgery. They also examined changes in brain metabolism associated with deep brain stimulation.
The researchers observed both early and progressive benefits with deep brain stimulation. For example, one month after surgery, 35 percent of the patients met criteria for response with 10 percent of patients in remission. Furthermore, six months after surgery, 60 percent of patients were responded to therapy and 35 percent met the criteria for remission. These benefits were largely maintained at 12 months.
Deep brain stimulation therapy was associated with specific changes in the metabolic activity localized to cortical and limbic circuits implicated in the pathogenesis of depression. The number of serious adverse effects was small with no patient experiencing permanent deficits.
The authors concluded that deep brain stimulation provides significant improvement in patients with treatment-resistant depression. The stimulation likely acts by modulating brain networks whose dysfunction leads to depression. They observed that the procedure was well-tolerated and benefits were sustained for at least one year.