Vagus nerve stimulation as a potential option for treatment-resistant depression

Despite the availability of numerous treatment options, many patients continue to suffer with chronic or recurrent major depression due to treatment non-response or intolerance. Several novel interventions for the treatment of mood disorders are under study, including vagus nerve stimulation (VNS). VNS involves intermittent electrical stimulation of the vagus nerve via the NeuroCybernetic Prosthesis system. This intervention has demonstrated acute and long-term safety and efficacy in the treatment of refractory epilepsy, and several lines of evidence suggest a role for VNS in the treatment of depression. Studies investigating the safety and efficacy of VNS in patients with treatment-resistant chronic or recurrent depression are currently underway, and results thus far are promising. This article provides an overview of VNS, including its current clinical uses, the rationale for studying VNS as a treatment for depression, current data regarding VNS in treatment-resistant depression, and suggestions for future directions of VNS in mood disorders.