Vagus nerve stimulation and deep brain stimulation: implantable device-related neurostimulation for treatment-resistant mood disorders

Vagus nerve stimulation (VNS) and deep brain stimulation (DBS) represent two surgical options for individuals with treatment-resistant unipolar and bipolar depression. VNS, a technology originally used in the treatment of epilepsy, involves the surgical implantation of an electrode to deliver intermittent stimulation to the left vagus nerve. Data from the use of VNS in those with mood disorders suggest that VNS confers a modest additional antidepressant effect to conventional treatments, and the effect grows over time. DBS, which involves the implantation of electrodes into discrete targets of the brain, is an established treatment for movement disorders such as Parkinson’s Disease. Data from open-label studies of DBS in mood disorder populations have been promising, although require replication in sham-controlled studies. Surgically implanted device-related neurostimulation techniques, such as VNS and DBS, represent promising therapeutic options for individuals with treatment-resistant depression who have failed to respond to conventional pharmacological and psychotherapeutic treatments.