Deep Brain Stimulation: Emerging Indications

Deep brain stimulation has become routine second-tier therapy in patients with Parkinson's disease, essential tremor and dystonia. In the past years, studies have begun to explore the applicability of DBS in emerging psychiatric indications such as addiction, Alzheimer's disease, consciousness, schizophrenia, aggressiveness and anorexia nervosa. In these psychiatric indications DBS is assumed to modulate dysfunctional neural structures or circuits. In the majority of corresponding case reports or phase I trials, DBS has produced beneficial effects. However, most psychiatric conditions have etiologies which are largely multi-factorial and cannot be reduced to single structures or circuits. Therefore, it is likely that the effectiveness of DBS will primarily consist of a reduction in specific symptoms linked to the neural site of modulation, rather than a global treatment. In this respect, it is too early to draw conclusions, which encourage or discourage the application of DBS in emerging psychiatric indications and the field will wait for well-designed clinical trials.