Psychosurgery Part 4: Vagus Nerve Stimulation

For Treatment Resistant Depression

In 1997, the FDA approved vagus nerve stimulation for epilepsy, and in 2005, it was approved for treatment resistant depression. Vagus nerve stimulation is a procedure that stimulates the vagus nerve1 with electrical impulses. (noticing a trend in electrical impulses and psychosurgery?) It is being worked on to treat Alzheimers, MS and migraines. There is one vagus nerve on each side of the body, running from your brainstem to your chest and abdomen2.

With vagus nerve stimulation, a device is surgically placed under the skin of your chest (similar to deep brain stimulation) and a wire connects to the left vagus nerve. After it’s activated, signals are sent to the vagus nerve and in turn, sent to various areas of the brain. Vagus nerve stimulation is used when epilepsy medications no longer work, or if depression is treatment resistant and everything else has been tried. (There is a link between epilepsy and mood disorders, I’ll get into that at a later date)

Since vagus nerve stimulation (VNS) has been FDA approved and is out of the clinical trial stage, the FDA has set rules for who may undergo the procedure. Here are the following criteria:

  • Age 12 and older (epilepsy)
  • Have partial epilepsy
  • Seizures that aren’t controlled by medications
  • Have treatment resistant (hard to control) depression
  • Haven’t improved after trying 4+ medications / ECT.
  • Continue standard depression treatments after the VNS procedure.3

This is a relatively safe procedure, but all procedures have risks. Some include: pain from the incision, infection, scarring, difficulty swallowing, vocal cord paralysis (sometimes permanent).

After the surgery, when the VNS is turned on and working, other side effects include: voice changes, hoarseness, throat pain, cough, headache, chest pain, breathing problems (especially while exercising), difficulty swallowing, abdominal pain or nausea, tingling or prickling of the skin, and I’ve heard rumours that it can cause spontaneous orgasms! (I can’t cite the source at the moment, or I would)

If the side effects don’t go away, the device can be turned off. You can change the amount of stimulation to help control side effects.

This actually isn’t brain surgery. One incision is made in the chest, for the pacemaker like tool, and another incision is done in the neck. This mayor may not be done under general anesthesia, it depends on the doctor and your own preferences. It takes one to two hours to perform the operation and it is done on an outpatient basis.

You are given a hand held magnetic device to turn the device on and off, and adjust the amount of stimulation running through the vagus nerve. You can turn it on and off at will, if you feel you need it. MRI’s are now out of the picture, except for the head in carefully monitored conditions.

This isn’t a cure, but there can be improvement of 30-50% in seizures and depression. Some treatments and medications may have to be used after the procedure.

We evaluated the efficacy and safety of vagus nerve stimulation therapyinthe treatment of 11 patients with chronic treatment-resistant depression. Mood was evaluated at frequent intervals over the year following implantation. All measures of depression, including the Hamilton Rating Scale for Depression reduced significantly. The response and remission rates were 55% and 27% respectively at 1 year. Side-effects were common, and some were severe

This study suggests that vagus nerve stimulation may be an effective treatment for some individuals suffering from chronic treatment-resistant depression. The response rates for the acute phase of the study were disappointing, in that only one patient responded after 3 months. By 1 year, 55% of the sample had responded to treatment, suggesting that long-term follow-up is required to realise the therapeutic potential of vagus nerve stimulation treatment. The placebo response in these patients was typically poor and so probably does not account for the response rate 4.”

Compared to the other psychosurgeries, this one seems to have quite a few serious side effects, but they should go away. It is reversible, which is a bonus, because once you’ve burned away cells in the brain, they don’t come back. If I really needed it, I would have his procedure done. It seems much safer, as they aren’t actually doing brain surgery. The time spent in the operating room and hospital is less and it is FDA approved for epilepsy and depression, where some other psychosurgeries are still going through clinical trials with no long term reports.


  1. The vagus nerve is responsible for speech, swallowing, breathing, monitoring the digestive process, acting as an anti-inflammatory, mood and some parts of body weight.