Brain Stimulation for Severe Depression

Chronic intracalvarial cortical stimulation is a minimally invasive method involving the neurosurgical placement of an electrode above the inner table of the skull. Over time, intracalvarial cortical stimulation is intermittently activated to modulate locally and distally connected brain regions. Because of the important role played by the dorsolateral prefrontal cortex in mood regulation, the goal of this study is to apply intracalvarial prefrontal cortical stimulation (IpCS) over the dorsolateral prefrontal cortex in severely treatment-resistant depressed (TRD) patients. Per the DSM-V and Centre for Medicare and Medicaid Services (CMS) nomenclatures, TRD patients are commonly defined as those whose treatment failed to produce response or remission after 2 or more attempts of sufficient duration and treatment dose. In the investigator's study, eligible TRD subjects will have a diagnosis of major depressive disorder with a suboptimal response to an adequate dose and duration of at least two different antidepressant treatment categories. These subjects will also have had exposure and transiently (non-durably) responded to non-invasive neurostimulation. The investigator anticipates that severely Treatment Resistant Depressed (TRD) Subjects with IpCS of the dorsolateral prefrontal cortex will show a significant decrease in depression symptoms as measured by the Montgomery-Asberg Depression Rating Scale (MADRS) at four months post-implant when compared to baseline. The investigator will enroll up to 20 subjects with severe refractory depression in an open trial, followed for up to one year. Depressive and cognitive symptoms will be rated periodically to assess the safety and efficacy of this procedure.