Vagus nerve stimulation: A new tool for treating depression

Vagus Nerve Stimulation (VNS) therapy was recently approved by the United States Food and Drug Administration as an adjunctive long-term treatment for patients with recurrent or chronic major depressive disorders who have failed at least, four antidepressant medication trials. Originally introduced as an effective treatment for refractory seizures, the device was investigated as a possible treatment for affective disorders. This investigation was based on the vagus nerve's anatomical projections in the brain; its effects on neurotransmitters, such as serotonin and norepinephrine; the use of anticonvulsants as mood stabilizers; and mood effects in some epilepsy patients who received VNS. Data indicate that long-term adjunctive VNS may improve the course of the illness for patients with major affective disorders. In general, treatment is well tolerated. The most common side effect is voice alteration and most side effects decrease or resolve with time. This article provides a clinical review of VNS therapy, including clinical trial data, side effects, and contraindications.