"Her depression controlled her life for the next 40 years -- until she decided to volunteer for an experimental treatment. A neurosurgeon would drill two holes in Guyton's skull and implant a pair of battery-powered electrodes deep inside her brain.
The procedure -- called deep brain stimulation, or DBS -- targets a small brain structure known as Area 25, the "ringleader" for the brain circuits that control our moods, according to neurologist Dr. Helen Mayberg.
Mayberg's groundbreaking research on this part of the brain showed that Area 25 is relatively overactive in depressed patients. So, Mayberg hypothesized that in patients who do not improve with other treatments, Area 25 was somehow stuck in overdrive."
http://www.cnn.com/2012/04/14/health/battery-powered-brain/index.html?hpt=hp_c1
