For nearly a decade, doctors have used an implanted
electronic stimulator to treat severe depression in people who don’t respond to
standard antidepressant therapy.
Now, preliminary brain scan studies conducted by researchers
at Washington University School of Medicine in St. Louis are beginning to
reveal the processes occurring in the brain during stimulation and may provide
some clues about how the device improves depression. They found that vagus
nerve stimulation brings about changes in brain metabolism weeks or even months
before patients begin to feel better.