The most anatomically discrete, and also the most invasive, method of stimulating deep brain structures is called deep brain stimulation (DBS). In this technique, a thin electrode is inserted directly into the brain and then different currents are applied at varying depth levels until the proper effects are found. This technique was used by some researchers in the US (31-33) as well as extensively by Russians. High frequency (>80Hz) electrical stimulation of the subthalamic nucleus has recently been shown to be effective in treating Parkinson’s Disease (34) and is now an FDA approved treatment. It has the clear advantage over brain surgery (pallidotomy) of being reversible. Direct comparisons of DBS with conventional brain surgery for PD show that DBS is more effective and has fewer side effects. Mood effects of DBS have been reported. For example, in one Parkinson’s patient who had never suffered from depression in her life, during the testing of stimulation, she noted the acute onset of tearfulness, sadness and despair, which immediately remitted when the surgeons moved the stimulator out away from the substantia nigra, directly below the subthalamic nucleus ( (35) and P. Damier, personal communication).