A Prospective, Multi-center, Randomized Controlled Blinded Trial Demonstrating the Safety and Effectiveness of VNS Therapy® System as Adjunctive Therapy Versus a No Stimulation Control in Subjects With Treatment-Resistant Depression

Objectives of this study are to determine whether active VNS Therapy treatment is superior to a no stimulation control in producing a reduction in baseline depressive symptom severity, based on multiple depression scale assessment tools at 12 months from randomization.