Vagus Nerve Stimulation is an interesting development for the treatment of treatment resistant depression. In the US it is approved by the FDA but not reimbursed by Health Insurance Companies, dividing psychiatric patients in haves and have nots?
A website with a lot of information on VNS at vnsdepression.com, please read the disclosure
For a discussion about efficacy of VNS and an update on the recent literature please read this post about VNS
Besides Electroconvulsive therapy, VNS is another form of Neurostimulation for depression
Other blogs are interested in VNS as well