|
This is a very technical article and may difficult to understand. There is very little in the medical literature about deep brain stimulation (DBS) for depression. It is in the very early stages of investigation. DBS is not an FDA approved procedure for depression and has only been tested on a few patients.
DBS is brain surgery and involves drilling a hole in the part of the brain known as Area 25. This part of the brain may have key implications in future treatments for patients suffering from very severe chronic depression.
Many depressed patients fail to respond to treatment despite continued advances in pharmacotherapy and psychotherapy. A Canadian partnership among neurologists, neurosurgeons, psychiatrists, and neuropsychologists investigated deep brain stimulation of the part of the brain known as Area 25 (below the genu of the corpus callosum) region of the cingulate gyrus in six patients with refractory major depression (mean Hamilton Depression Rating Scale score of moderate-to-severe depression and an average duration of current episode, 5.6 years). Patients had not responded to adequate courses of at least four different therapies, including cognitive-behavioral therapy, antidepressants, ECT (n=5), and augmentation with lithium, anticonvulsants, or atypical antipsychotics.
Four electrodes were implanted bilaterally in the transitional region between neuron-dense and neuron-sparse regions of Area 25). A single-blind protocol was used to determine the optimal voltage, electrodes for stimulation, and frequency of stimulation for each patient; intraoperatively, patients reported feeling immediately better with actual but not sham stimulation. Patients then received stimulation during the next 6 months; their preoperative medications were continued.
Four patients had a sustained response, including two who achieved remission at 6 months. Compared with baseline findings, stimulation reduced regional cerebral blood flow in Area 25 in four patients and increased prefrontal regional blood flow in three long-term responders. The patient with the most robust response underwent single-blind discontinuation of stimulation; he eventually began to show signs of relapse but responded again to active treatment.
Area 25 interacts with the orbitofrontal, prefrontal, medial, brainstem, hypothalamic, and other regions, and apparently aids in modulating negative mood states. As with other antidepressant therapies, stimulation normalized cerebral blood flow. The study had important limitations, including lack of a control group and double-blind protocol, small number of patients, and inclusion of patients who were not very severely depressed.
However, further investigation of innovative approaches that would not require permanent lesions is clearly warranted.
Source
Mayberg HS et al. Deep brain stimulation for treatment-resistant depression. Neuron 2005 Mar 3; 45:651-60.
|
