While Vagus Nerve Stimulation (VNS) is an FDA-approved therapy and already available on the market, it is not yet covered by Medicaid/Medicare services. Simultaneously, treatment-resistant depression (TRD) patients face limited treatment options and a significantly reduced quality of life. Hence by trialling Vagus Nerve stimulation’s effect on Bipolar treatment resistant Depression, we may determine if there are significant and satisfactory clinical outcomes to justify its coverage. This study aims to question if active VNS therapy, as an adjunct to treatment as usual, leads to a significant reduction in symptom severity and suicidality in patients with TRD over the first 18 months of treatment.

This analysis focuses on the first 18 months of a mandated 5-year, double-blind, sham-controlled trial. Participants with bipolar TRD who had failed four or more antidepressant treatments were surgically implanted with a VNS generator. They were randomized to receive either active or sham stimulation for the first 12 months, after which all devices were activated. The study assessed changes in symptom severity (measured by the Clinical Global Impression – Improvement Scale, CGI-I) and suicidality (measured by the Sheehan Suicidality Tracking Scale) as an adjunct to treatment as usual.

No statistically significant reduction in suicidality was observed over the 18-month period. However, analysis of the CGI-I scores indicated a significant reduction in overall symptom severity. This improvement was significantly greater following the activation of the VNS implant compared to pre-activation baselines.

These preliminary 18-month data suggest that adjunctive VNS Therapy may yield significant benefits in reducing symptom severity, though not suicidality, in a highly treatment-resistant bipolar depression population. These findings are a critical step in evaluating the therapy's potential for providing clinically meaningful outcomes for Medicare beneficiaries.