Vagus nerve stimulation in chronic treatment-resistant depression: preliminary findings of an open-label study.

We evaluated the efficacy and safety of vagus nerve stimulation therapy in the treatment of 11 patients with chronic treatment-resistant depression. Mood was evaluated at frequent intervals over the year following implantation. All measures of depression, including the Hamilton Rating Scale for Depression reduced significantly. The response and remission rates were 55% and 27% respectively at 1 year. Side-effects were common, and some were severe.