Vagus nerve stimulation for depression: efficacy and safety in a European study

Area of Science:

• Neurology
• Psychiatry
• Medical Devices

Background:

• Vagus nerve stimulation (VNS) therapy is recognized for reducing seizure frequency in epilepsy.
• Preliminary studies indicate VNS therapy's potential as a low-side-effect treatment for intractable depression.

Purpose of the Study:

• To evaluate the efficacy and safety of VNS therapy in patients with treatment-resistant depression (TRD).
• To assess the long-term effectiveness of VNS therapy over a 12-month period.

Main Methods:

• An open, uncontrolled, multi-centre European study involved 74 patients with TRD receiving VNS therapy alongside stable pharmacotherapy.
• Patient treatment was maintained for 3 months, followed by 9 months of potential adjustments to medications and VNS parameters.

Main Results:

• After 3 months, VNS therapy achieved 37% response and 17% remission rates (HAMD-28 scores).
• By 12 months, response rates increased to 53% and remission rates to 33%, with 44% achieving sustained response.
• Common side-effects included voice alteration (63%) and coughing (23%) at 3 months.

Conclusions:

• VNS therapy demonstrates effectiveness in reducing depression severity, with benefits increasing over time.
• The European study's efficacy aligns with previous US findings, showing significantly greater symptom reduction at 12 months.
• Differences in baseline scores and treatment history may explain enhanced efficacy in the European cohort.