For the full picture on AntiDepressants, see here -
http://www.depression-management.inf...pressants.html

info below is from what is the best website I've even encountered on Depression --
http://www.depression-management.info/

Vagus Nerve Stimulation (VNS) Therapy

The FDA approved the VNS Therapy System by Cyberonics, Inc. in July 2005 as an adjunctive long-term treatment for adults with chronic or recurrent treatment-resistant major depression (those who have not had an adequate response to at least four courses of conventional antidepressant treatments).
The FDA's post approval requirements include post approval studies - one study will follow 1000 patients receiving VNS therapy for five years. Click here to view the FDA's approval letter. At the end of this 5-year study of 1000 patients, they will reappraise their approval.

The main reason it was approved is that its use in epilepsy has a long period of verying basic safety, but it has not yet have proven results.

VNS Therapy has been in use in the U.S. since 1997 as an adjunctive treatment of difficult-to-control epilepsy. Some of these patients (being treated for epilepsy) have reported improvement in mood, alertness, and memory.

These benefits may be due to improved seizure control or may be a direct result of VNS therapy - or a combination of both. In other words, the reports of patients may reflect an artifact of the alleviation of epileptic seizure activity. VNS Therapy has been approved for use in Europe and Canada for treatment-resistant depression since 2001.

What is VNS Therapy?
VNS therapy involves stimulating the vagus nerve, which in turn stimulates brain. The vagus nerve extends from the brain through the neck to the major organs - a major communication link between the brain and body.

A small battery-powered device (a pulse generator) similar to a pacemaker is surgically implanted in the chest, connected by a lead to electrodes that connect to the left vagus nerve in the neck. The device sends small periodic electrical pulses to the vagus nerve, which delivers these electrical pulses to the brain. The pulse generator can be programmed externally by a computer, and can be turned off with a special magnet.

How Does VSN Therapy Relieve Depression:
It is not known exactly how VNS therapy relieves depressive symptoms in some people. Stimulating the vagus nerve and the brain through the vagus nerve may trigger the brain to release mood-regulating neurotransmitters or alter the way in which they are transmitted.

How Effective is VNS Therapy for Major Depression?

It appears that 30 - 33 % implanted with a VNS Therapy system report at least a 50% reduction in symptoms of depression.

Only 15% of patients will have full or nearly full remission of the symptoms of depression. Many (but not all) of these patients were still being as well benefitted 2 years after the surgery.

67 - 70% will have no reduction in depression or less than a 50% improvement.

• There is no way to predict which patients will respond to VNS therapy.
• It may take several months before any benefits are noted.
• Improvements may not last.
• Some people may not benefit at all.
• Some people may even get worse.
• There are risks and side effects and special precautions must be taken.

PRECAUTIONS:

• VNS Therapy system may interfere with other implanted devices such as cardiac pacemakers.
• If a person with a VNS therapy device needs an MRI, special precautions must be taken. A person with a VNS stimulator should not have a full body MRI.
• A person with a VNS therapy device cannot have diathermy. This includes short-wave diathermy, microwave diathermy, or ultrasound diathermy (diagnostic ultrasound is still safe). Diathermy is a therapy (often used by physical therapists) used to treat pain, stiffness, etc, in which a device is applied externally to deliver energy into a person’s body. Diathermy may cause any part of the VNS therapy system to heat up and cause temporary or permanent damage to tissue, nerves, or blood vessels – even if the VNS therapy device is turned off. If there is damage to blood vessels, death could occur. Any part of the system is subject to overheating from diathermy.
• Even if the pulse generator is removed, the lead (small wires) and electrodes attached to the vagus nerve may be left in place (to avoid damaging the vagus nerve) and special precautions must still be taken in regards to diagnostic MRIs and diathermy treatments.

Click here for the Depression Patients Manual for the VNS TherapyTM System by Cyberonics, Inc. This article is a pdf file written up by the FDA (the Food & Drug Administration of the govenment).