"A procedure that involves drilling two holes into a person's skull and
then implanting electrodes in the brain has shown promise in treating
individuals who are severely depressed and resistant to other types of
treatment.
...
Lozano drilled two small holes into each side of the skull in a two-hour
procedure that took place under local anesthesia. He inserted two thin
wires with electrode contacts, then tunneled the wires (about the diameter
of uncooked spaghetti) underneath the skin behind the ear down to the
chest. An incision was made under the collarbone so a battery could be
placed there. The electrodes were hooked up to the batteries (one on each
side of the body). The batteries can be programmed remotely through the
skin  ... Stimulation ... takes place 24 hours a day.
...
NAMI has more on major depression."

http://www.forbes.com/lifestyle/health/feeds/hscout/2005/03/01/hscout524275.html

(Of interest to me is that this is being reported in Forbes, a magazine for
"the world's business leaders"  S.)

People Who experience mood swings, fear,
voices and visions: each other on the internet
www.peoplewho.org