Stimulating the Brain

We’ve known about magnetism itself for a long time. We’ve used it and relied upon it for centuries. We even understand how it works. Still it continues to fascinate and mystify us. There was even a time when some people believed that magnetism could control the mind.

But transcranial magnetic stimulation is not science fiction nor is it a new age fad. It’s a safe, non-invasive procedure that uses electromagnetic energy to stimulate the brain. TMS has been used in research since 1985. Since the late 1990s, it’s also been used clinically, not only as a treatment for depression, but for several other conditions as well.

We already have a treatment that uses electricity to stimulate the brain. Electroconvulsive therapy (ECT) has been around for over 70 years and is still considered to be the “gold standard” for treatment of severe depression. Although it is generally regarded as being effective, it is interesting to note that ECT was approved for use before the FDA existed. There have been no randomized controlled studies regarding the effectiveness of ECT since the 1980s. In fact, the FDA is currently considering reclassifying ECT devices and possibly requiring new studies to be done in order to demonstrate safety and efficacy.

In recent years, implanted electrodes have also been introduced, such as the vagus nerve stimulator (VNS). This is a very invasive treatment that involves surgically implanting the device in the neck and attaching it to the vagus nerve. Although it has been approved by the FDA, it is rarely used, not only because of concerns about safety, but also because it has not been very effective. Another still experimental device for treating depression is deep brain stimulation, which is also a neurosurgical procedure that is very risky and highly invasive.

Not only is TMS safe and effective, but it doesn’t even involve the use of electrodes. That’s because electricity and magnetism are two different aspects of the same phenomenon. Every electrical current generates a magnetic field and a magnetic field can cause an electrical current to flow in a nearby conductor. This was discovered almost 200 years ago by the English physicist Michael Faraday.

TMS takes advantage of this relationship between electricity and magnetism by using an electrical current to generate a magnetic field which then induces an electrical current in the brain. So transcranial magnetic stimulation is actually transcranial electrical stimulation, but without the use of electrodes. The therapeutic effect from TMS doesn’t come from the magnetic field itself but rather, from the electrical current which it induces. 

Introduction to TMS-The Problem of Depression

In 25 years of clinical practice I have not seen a treatment for medication resistant depression which is as safe and as effective as transcranial magnetic stimulation (TMS). It has now been one year since I decided to make a major career change and devote my practice primarily to TMS. I continue to see the same excellent results that prompted me to make that career change and in this next series of posts, I will focus on TMS.

The Problem of Depression

Depression is a major public health problem. In the United States, almost 20 million people have some form of depression. Only about half will ever be treated and of those, only about half will make a full recovery. Even with treatment, depression can still mean a lifetime of suffering.

But the full impact of depression is even greater than most people realize. According to the World Health Organization, in 2004 depression was already the world’s third leading cause of disability and by the year 2030, it’s expected to be the leading cause. In this country, depression is already the leading cause of disability for people between the ages of 15 and 55. Most of them are not dealing with the acute symptoms of an acute episode but instead are struggling with the chronic and persistent symptoms of treatment resistant depression. In October 2008, the FDA approved the use of transcranial magnetic stimulation specifically for treatment resistant depression.

TMS at the 2010 APA Meeting in New Orleans

I just returned from New Orleans where I attended the 163rd annual meeting of the American Psychiatric Association. As expected, New Orleans was hot and humid but every bit as fun as I remembered from my last visit before Katrina. It was great to see old friends and colleagues and to meet new ones for the first time.

This year I participated in several important events.  On Sunday, I had the honor of giving a brief presentation about my TMS experience to everyone who attended the 60 Million Pulse dinner hosted by Neuronetics. That was a fun event, but on Monday I was part of a more serious panel discussion about the use of TMS in clinical practice with my esteemed colleagues Dr. Timothy Derstine of State College, PA; Dr. Carl Wahlstrom of Chicago, IL; and Dr. Todd Hutton of Pasadena, CA. 

All of us have been using TMS since shortly after it was cleared by the FDA and we had the opportunity to share some of our clinical experiences thus far. Although all of us have had the satisfaction of seeing our patients respond to TMS, it was interesting to see how our experiences differed in certain ways. For instance, I was the only one on the panel to have had the experience of treating adolescent and geriatric patients. Many in the audience were psychiatrists who have been thinking about adding TMS to their practice but some had more experience with TMS than any of us on the panel. I was especially pleased to meet Dr. Alexander Lyford-Pike from Montevideo, Uruguay. 

On Monday evening I demonstrated the use of the Neurostar TMS Therapy device at a press briefing and throughout the meeting I had the opportunity to introduce colleagues to TMS through brief presentations at the Neuronetics information booth. 

Among the scientific papers presented at the meeting, Drs. Mark George, Sarah Lysanby, and Ziad Nahas reviewed the findings from a major study published in this month’s Archives of General Psychiatry, which demonstrated that patients with treatment resistant depression are more than 4 times as likely to respond to TMS as they are to another medication trial. This study was noteworthy for several reasons. First of all, it was one of the largest, multisite, randomized controlled studies of TMS to ever be performed. It was sponsored by the National Institutes of Health. It used a much more sophisticated sham TMS control than any previous TMS studies. And it was published in one of the most important peer reviewed psychiatry journals in the world.  

All in all, this year’s APA meeting was an interesting and rewarding time. When I started doing TMS back in January 2009, I was only one of about a dozen doctors in the country using the newly approved Neurostar device. Now there are 190 Neurostars around the country. I am glad that this important and highly effective treatment is now available to so many people. Although routine insurance coverage is still probably about a year away, more and more insurance companies are paying for TMS as it becomes increasingly clear that TMS is, in fact, a major advance in modern psychiatric medicine.

Beginning with my next post, I will describe in detail how TMS was developed and how it evolved to become a truly revolutionary treatment for depression and how it may one day revolutionize the treatment of a range of other neuropsychiatric conditions.