http://www.chron.com/cs/CDA/ssistory.mpl/business/3268590Vagus nerve impulses
The watch-size device, which looks somewhat like a pacemaker and is implanted in the chest, sends pre-programmed intermittent impulses through the vagus nerve in the neck to the brain.
"It is a significant event for the company," said Keay Nakae, an analyst with C.E. Unterberg, Towbin in San Francisco. "They have spent a lot of time and effort and money trying to develop and get approval for this indication. This represents a particularly large market for the company."
Cyberonics President Robert "Skip" Cummins could not be reached, but in a prepared statement he said the approval meant much-needed relief for those who suffer from the very darkest forms of depression.
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depression is pain. so i guess if you could turn that pain off, it would be beneficial. i wish they had such an implant to turn off the physical pain centers of the brain, so drugs wouldn't be needed.
but then, we are altering the things which make us human. but we do that anyway with artificial hip joints, pacemakers, etc. sci fi writers have been thinking about this for a century, and how far it could be taken in the future.