Deep brain stimulation (DBS) was first developed as a treatment for Parkinson's disease to reduce tremor, stiffness, walking problems and uncontrollable movements. In DBS, a pair of electrodes is implanted in the brain and controlled by a generator that is implanted in the chest. Stimulation is continuous and its frequency and level is customized to the individual.

DBS has only recently been studied as a treatment for depression or obsessive compulsive disorder (OCD). Currently, it is available on an experimental basis only. So far, very little research has been conducted to test DBS for depression treatment, but the few studies that have been conducted show that the treatment may be promising. One small trial involving people with severe, treatment-resistant depression found that four out of six participants showed marked improvement in their symptoms either immediately after the procedure, or soon after. Another study involving 10 people with OCD found continued improvement among the majority three years after the surgery.