Managing patients with psychiatric conditions treated with deep brain stimulation

Introduction: Psychiatric disorders, particularly depression and obsessive–compulsive disorder (OCD), are the newest frontier for DBS. The evidence base for specific anatomical targets or disease indications remains fluid, as few centers have the technical expertise and cross-disciplinary integration required to explore the boundaries of clinical knowledge. As such, most use of DBS for psychiatric conditions occurs under the auspices of a clinical trial. The one exception is OCD, where a Humanitarian Device Exemption (HDE) from the US Food and Drug Administration permits OCD treatment with stimulation of the anterior limb of the internal capsule – most often referred to by clinician-investigators in the field as ventral capsule/ventral striatum (VC/VS). Even in that approved context, DBS treatment requires exceptional care in patient selection, with special considerations not usually found in the use of DBS to treat movement disorders. Further, neurostimulator programming for psychiatric indications is more complex and time-consuming. Patients’ symptoms do not immediately change in response to parameter adjustments, requiring clinician and patient to collaborate over extended periods to identify optimal settings. In this chapter, we will briefly review the origins and evolution of DBS for psychiatric illness, beginning with targeted lesion procedures and progressing to present-day device-based neuromodulation interventions. That discussion will focus on depression and OCD, the only two diagnoses that have to date been subjected to adequately controlled and well-conducted studies. We will then describe appropriate procedures for patient selection, including the criteria that we use in our evaluations and that have been the basis for both standard clinical care and controlled clinical trials. This will be followed by a discussion of DBS device programming, with a particular focus on the integration of DBS and standard psychiatric management to achieve clinical goals. For the interested reader, we conclude with a preview of expected developments in this rapidly progressing field, particularly those that may change clinical practice in coming years. Historical overview: The use of DBS to treat psychiatric conditions draws on two well-established research traditions: lesion/ablation surgeries and brain imaging that seeks to inform the circuits underlying mental illness. The former field, often referred to as “psychosurgery” or “psychiatric neurosurgery,” remains relatively stigmatized, largely due to abuses of clinical privilege in the early to middle twentieth century.