The majority of patients who respond to vagus nerve stimulation as therapy for treatment-resistant depression will maintain their improvements for at least 24 months, according to a presentation at the annual meeting of the American Psychiatric Association.

The current analysis used pooled data from previous studies of patients whose depression was characterized by exceptional levels of chronicity and treatment-resistance. Between 61 percent and 79 percent of patients who responded to therapy maintained response at 24 months. The durability of benefit was not attributable to alterations in other treatments.

Electroconvulsive therapy is considered by many psychiatrists as the most effective acute intervention for treatment-resistant depression. However, the majority of patients relapse during the first year following response to electroconvulsive therapy.

"These data showing durability of response with vagus nerve stimulation therapy are rather remarkable under any circumstance, but particularly for the patient population studied here," said Harold A. Sackeim, PhD, of Columbia University. "These findings regarding long-term sustained effectiveness are very encouraging for psychiatrists, patients with treatment-resistant depression, and for payers, all of whom are looking for more effective and cost-effective treatment options for chronic or recurrent depressions that have failed to respond or sustain a response to multiple treatments."

"This research highlights a unique and one of the most valuable attributes of vagus nerve stimulation therapy," added Stephen K. Brannan, M.D., Medical Director, Cyberonics, the device manufacturer.

"Many patients who did not achieve a response or sustain a response during some 20 years of treatment with over 15 different antidepressants not only responded to vagus nerve stimulation therapy, but sustained that response out to two years. These findings, combined with the decreases in suicidality and hospitalizations due to worsening depression also reported here at APA, confirm the positive effect that vagus nerve stimulation therapy has on long-term treatment-resistant depression patient outcomes and healthcare utilization."

The US has approved vagus nerve stimulation therapy as an adjunctive long-term treatment of chronic or recurrent depression for patients 18 years of age or older who are experiencing a major depressive episode and have not had an adequate response to four or more adequate antidepressant treatments. vagus nerve stimulation is the first FDA-approved implantable device-based treatment for depression and the first treatment developed, studied, approved and labeled specifically for patients with treatment-resistant depression.