it just felt great. >> spoon that in there. >> since 2003, maberg studied 37 patients with two-thirds showing significant improvement. >> pretty good, huh? >> i don't feel good all the time but this gives me the capacity that if i can if there is joy in my life i have the capacity to feel it. >> what exactly is dbs doing to the brain circuits? >> what do we and don't we know why this works? >> to be brutally honest, we have no idea how it works. >> while mayberg continues her research to unlock the secrets of area 25, it's been five good years for edi guyton. >> aww. >> if you hadn't had the operation where would you be right now? >> i really believe that i would have committed suicide. >> edi's transformation is so dramatic. for now as you might guess the procedure is still experimental, two medical device companies that are conducting larger studies, have the hope of winning fda approval, but that is several years away. >>> much more of this reporting on battery powered brains, sunday night, cnn presents 8:00 and 11 clock eastern. >>> stephanie joins me to funny piece for our websit

helen maberg, who believes she discovered that area.atients, randi, who had no options, medications have nod worked, electroconvulsive therapy stopped working she decided to stimulate that part of the brain and got astonishing results. i'll show you real quickly, this is what it looks like, a battery pack, it would sit under someone's collar bone under the skin. this here is in fact what goes in the brain. >> she is putting that in patients? >> she is with the help of a neurosurgeon, putting these in the brains. there are several electrodes, she would stimulate different amounts of electricity and try to get some benefit in the patients and she saw that several times. it was remarkable. >> there is a real difference once you put that in, she can say it has been successful? >> she can. and i saw some of this myself and it was profound. this one woman who you can see more this weekend, she really had been in a profound state of depression for a long time, had no connection with family, people around her, and even in the operating room, al