Vagus nerve stimulation therapy in a patient with treatment-resistant depression: a case report of long-term follow-up and battery end-of-service.

This is the first case report of a patient who received long-term (69-month) adjunctive vagus nerve stimulation (VNS) therapy for treatment-resistant depression (TRD) and reached VNS battery end-of-service (EOS).The patient is a 41-year-old female with depression who entered a study of adjunctive VNS therapy for TRD. Her Hamilton Rating Scale for Depression (HAM-D) scores dropped from a mean of 33.5 (pre-implantation baseline period) to 16 at the end of the 12-week acute-phase treatment period, and then fluctuated from