Magnetic Relief For Depression?
Tuesday, November 11, 2008
Steve Newman had suffered from major depression from the time he was 13. He tried innumerable treatments: psychotherapy and medications. Approaching 60, single by necessity and friendless by choice, he decided his train had only two stops left before suicide.
One option was shock therapy, formally known as electroconvulsive therapy, or ECT. The controversial technique has been shown to be effective in treating depression, but it involves inducing seizures in patients. Memory loss is a common side effect. Newman was not looking forward to it.
Newman was working in Florida as an insurance agent when he heard about the other option. It sounded like science fiction, or just kooky: Scientists in this country and overseas were experimenting with the use of high-power magnets to cure depression, using a technique known as transcranial magnetic stimulation, or TMS.
"I would have jumped into a volcano to get better; my life was just unbearable," Newman said. "I was at the point in my life where I did not have a lot of choice. I decided I would try TMS and then ECT, and if neither of them worked, I was going to consider suicide."
Newman gave up his job in Florida and in 2005 moved to Philadelphia, where he signed up for the magnetic therapy trial at the University of Pennsylvania. Weeks after the treatments began, Newman said, he woke up one morning and found that his depression had vanished.
"It was like a light switch went on and I had my life back," said Newman, who now lives in Northwest Washington and works at the National Institutes of Health.
In October, the Food and Drug Administration approved the magnetic therapy as a treatment for major depression. Many scientists believe that the technique is a harbinger of things to come. Already, researchers are probing its effects on schizophrenia, post-traumatic stress disorder and bipolar disorder, or manic depression.
The basic principle behind the treatment is less kooky than it sounds and comes not from psychiatry but physics -- specifically, the 19th-century discovery of the principle of electromagnetism. British physicist Michael Faraday and others found that when a magnet was suspended around a wire carrying an electric current, the magnet tended to rotate. Conversely, when a magnetic field moves around a coil, an electric current is induced in the wire. The principle of electromagnetism suggests that electricity and magnetism are linked phenomena.
TMS uses the principle of electromagnetism to induce small electric currents inside the brain. Patients such as Newman are seated in what looks like a dentist's chair and have a magnetic coil placed near the left side of their foreheads. A powerful, fluctuating magnetic field is then started.
Since neurons, or nerve cells, are electrochemical agents (they transmit bursts of energy in systematic patterns using chemical signaling), the magnetic field stimulates them. This, in turn, alters blood flow and metabolic activity in the brain. In the trial Newman participated in, patients received about 3,000 rapid magnetic pulses in just under 40 minutes. Doctors aimed the magnetic field at patients' left prefrontal cortex (around the left temple), a brain area that has been implicated in depression. Patients sometimes reported a tingling in their scalp or slight pain.
"When you think of psychiatric illnesses and the brain, therapy has been dominated by the use of chemicals, but when you give an antidepressant, the pill alters the electrochemical properties of the cell," said Mark Demitrack, chief medical officer at Neuronetics Inc., the Malvern, Pa., company that has developed the recently approved magnetic therapy device, called NeuroStar. "This is the flip side of the same coin. It is just a different way of getting at the same end effect: to change, restore or alter the functioning of nerve cells."
No one really knows what is specifically happening in the brain to cause depression, and no one really knows why TMS, psychotherapy and other treatments work. Like a host of psychiatric medications that have been discovered through serendipity, the effect of powerful magnetic fields on mood was discovered by chance. Doctors don't like this analogy, but a lot of psychiatric treatments for depression are somewhat akin to banging the side of a blurry TV; even if you don't know why it helps, it sometimes clears up the signal.