The letters O-C-D have become a punch line to describe people who make lists or wash their hands a lot. But for some people with obsessive-compulsive disorder, the intrusive thoughts and rituals are severely disabling and don't respond to drugs or behavioral therapies.
So doctors have been trying a new treatment for OCD: deep brain stimulation.
Deep brain stimulation is best known as a way to reduce the tremors of Parkinson's disease. A surgeon places wires deep in the brain that carry electrical impulses from an implanted device a bit like a pacemaker.