Electrical Brain Stimulator Helps Resistant Depression
A recent study of individuals with drug and treatment-resistant depression that received Deep Brain Stimulation (DBS) in the subcallosal cingulate region of the brain (SCG or Cg25) indicates that deep brain stimulation is relatively safe and results in improvement in patients about one month after treatment. The improvement in the depression continued during the one year follow up period.
The report was made in Biological Psychiatry by researchers from the University of Toronto and Emory University School of Medicine in Atlanta, Georgia.
The research started at the University of Toronto in 2002, directed by Dr. Helen S. Mayberg, MD, and other researchers including Andres Lozano, MD, PhD, neurosurgeon, and psychiatrist Sidney Kennedy, MD.
Dr. Mayberg is a professor in the Department of Psychiatry and Behavioral Sciences and the Department of Neurology at Emory University School of Medicine. Dr. Mayberg has done 20 years of research involving brain imaging that has sought to characterize brain abnormalities in major depression as well as to understand the mechanisms of various antidepressant treatments.
Deep Brain Stimulation uses high-frequency electrical pulses to target specific areas of the brain that are involved in neuropsychiatric diseases. Twenty individuals with depression received Deep Brain Stimulation for 12 months. Twelve of 20 patients had a significant improvement in depression symptoms ( using the Hamilton Depression rating scale–50 percent decrease) at six months. Seven patients were essentially well with few remaining depression symptoms (remission according to the Hamilton Depression Rating Scale). The remarkable improvement was still present at 12 months with continuing Deep Brain Stimulation. It also appears that there were no long term side effects with this treatment.
Patient had two thin wire electrodes surgically placed on each side of the brain near to subcallosal cingulate region. The wires were connected under the skin to a pulse generator that was implanted in the chest (much like a pacemaker). The scientists adjusted the intensity of the electrical stimulation based on the response of the patient. Study participants were those who had tried other conventional treatments for depression but were unable to get better. The failed treatments included medication, conventional psychotherapy and electroconvulsive therapy.
The scientists knew that the subcallosal cingulate region of the brain was a key region involved in major depression.
The doctors were able to follow the clinical response of the patients over a 12-month period using standard depression rating scales. The researchers also used neuro-psychological testing and scanning of both regional brain blood flow and glucose metabolism using positron emission tomography (PET scan).
PET scan images of these patients revealed that metabolic activity changed near the site of stimulation and throughout the previously identified depression network in the brain.
Depression is a complex disturbance of specific circuits in the brain responsible which regulate mood and emotions, according to Dr. Mayberg.
Mayberg initiated a larger version of her Toronto study at Emory in 2007. The new Emory University study will look at a number of additional ideas including the testing of patients with bipolar II depression and further refinement of the brain targeting.
Emory University Press Release
