Effectively treats movement disorders and could work in neuropsychiatric conditions Neurological and psychiatric illnesses continue to cause major disability despite currently available treatment options. With this background of unmet treatment need, important advances in structural and functional brain imaging, the understanding of the circuitry of neurological disease, and neurosurgical techniques and equipment have led to the emergence of deep brain stimulation (DBS) as an effective therapeutic option. Deep brain stimulation was first tested in animal experiments about 70 years ago and has been used in human subjects, mainly to treat movement disorders—particularly Parkinson’s disease—for the past 20 years. It is now available in most major medical centres. More than 80 000 patients have undergone such stimulation to date,1 and 8000-10 000 new patients are treated each year. Deep brain stimulation involves implanting indwelling electrodes within specific brain circuits to modulate the activity of those circuits, either to suppress pathological neuronal activity or to drive underactive output; an analogy would be moving the dial to a chosen radio station and adjusting the volume when the sound is too low …