Implanted vagus nerve stimulation for treatment-resistant depression

Evidence-based recommendations on vagus nerve stimulation for treatment-resistant depression in adults. This involves implanting an electrical stimulator under the skin of the chest and connecting it by wires to the vagus nerve.

# Recommendations
Evidence on the safety of implanted vagus nerve stimulation for treatment-resistant depression raises no major safety concerns, but there are frequent, well-recognised side effects. Evidence on its efficacy is limited in quality. Therefore, this procedure should only be used with special arrangements for clinical governance, consent, and audit or research. Find out what special arrangements mean on the NICE website.
Clinicians wishing to do implanted vagus nerve stimulation for treatment-resistant depression should:
Inform the clinical governance leads in their NHS trusts.
Give patients clear written information to support shared decision making, including NICE's information for the public.
Ensure that patients understand the procedure's safety and efficacy, as well as any uncertainties about these.
Audit and review clinical outcomes of all patients having the procedure. NICE has identified relevant audit criteria and is developing an audit tool (which is for use at local discretion).
NICE encourages further research into implanted vagus nerve stimulation for treatment-resistant depression, in the form of randomised controlled trials with a placebo or sham stimulation arm. Studies should report details of patient selection. Outcomes should include validated depression rating scales, patient-reported quality of life, time to onset of effect and duration of effect, and any changes in concurrent treatments.# The condition, current treatments and procedure

# The condition
Depression is characterised by low mood, loss of interest and enjoyment in life, and a range of associated emotional, cognitive, physical and behavioural symptoms. Depression is treatment-resistant when symptoms have not improved after at least 2 standard treatments.

# Current treatments
The diagnosis and management of depression is described in the NICE guideline for depression in adults and the NICE guideline for depression in children and young people. Standard treatment for depression includes antidepressants or psychological therapies (including cognitive behavioural therapies) or a combination of both. In severe depression when multiple treatments have failed, electroconvulsive therapy or other forms of neurostimulation are sometimes used.

# The procedure
The aim of implanted vagus nerve stimulation for treatment-resistant depression is to reduce symptoms and improve mood by periodic stimulation of the vagus nerve.
The procedure is done using general or local anaesthesia. An incision is made on the left side of the neck and the left vagus nerve is identified. A stimulator electrode is put around the nerve and the leads of the electrode are guided under the skin to the left chest wall. They are attached to a pulse generator unit, which is implanted into a subcutaneous pocket. The stimulator settings can be adjusted or turned off using an external (wireless) programming device.