Now, research is advancing rapidly on a host of far more precise techniques to stimulate or calm the brain with electricity, magnets or even ultrasound and infrared waves. Most of the therapies target severe, resistant depression—a problem for nearly seven million Americans. But some are also showing promise for treating obsessive-compulsive disorder, panic disorders, schizophrenia, addictions and memory problems.
Some battery-operated brain stimulators are even being marketed for home use, so patients can treat their own depression and insomnia, though some neurologists say the evidence for these devices is thin.
"There's a stampede of these new technologies," says Mark George, a psychiatrist and neurologist at the Medical University of South Carolina and editor-in-chief of the journal Brain Stimulation. "There are all these different ways to get into the brain and figure out how to change the circuits."
Indeed, there's a growing consensus among neuroscientists that many psychiatric illnesses stem from problems in the brain's electrical circuits.
"In psychiatry, we have gone from 'It's all about your mother' a la Freud to the concept of chemical imbalances in the brain to the current focus on dysfunctional brain circuits and genetics," says Emory University neurologist Helen Mayberg, a pioneer in brain imaging and depression.
But much still isn't known, she adds. "What regions are in the game? How are they wired up? Which ones are most important to which problem?"
Using fMRIs, PET scans and other imaging technologies, neuroscientists also hope they can someday predict which patients will respond to which treatments—without having to endure years of trial and error.
At the same time, electroconvulsive therapy (ECT), the decades-old practice of using electric current to trigger a brief brain seizure, is set to face new scrutiny at a Food and Drug Administration hearing later this month. The treatment was grandfathered by the agency in 1976 without the kind of lengthy, expensive clinical trials required today. With some longtime critics charging that ECT causes cognitive defects and dementia in patients, the FDA could require that the few makers of ECT equipment run such studies now—but the companies have warned that they can't afford such research.
"The reason we still have ECT is that we need it. It's the most rapidly acting and effective approved treatment we have for major depression," says Duke University Medical Center psychiatry chairwoman Sarah Lisanby, one of many who fear that suicides might rise if ECT were unavailable. Once known for blunting personalities and breaking bones, ECT has become much safer in recent years. Patients now undergo general anesthesia, the current is far more controlled and it is often applied only on one side to minimize memory loss. More than 100,000 ECT procedures are conducted annually in the U.S.
Of the new brain-stimulation therapies, the most developed is Transcranial Magnetic Stimulation (TMS), cleared by the FDA in 2008 to treat patients who had failed on one anti-depressant. A technician holds a magnetic coil against the patient's forehead. Short electromagnetic pulses, about the strength of an MRI, travel through the skull and stimulate nerve cells in the brain's dorsal lateral prefrontal cortex, an area thought to be involved in depression. Patients feel only a slight tingling; they typically undergo 40-minute treatments daily for four to six weeks.
Peer-reviewed studies show that TMS results in remission in about 30% of depressed patients, only half the rate of ECT but twice as good as a placebo. Common side effects include headaches and scalp irritation; long-term effects are still unknown. To date, about 3,000 patients have been treated with TMS, according to Neuronetics Inc., which makes the device, and 70 insurers have covered on a case-by-case basis.
Two brain-stimulation techniques require surgery:
With Vagus Nerve Stimulation (VNS), a pacemaker-like device is implanted near the base of the neck to deliver mild electrical pulses to the vagus nerve, which tells the brain what's going on in the rest of the body. A study in the journal Appetite in the fall found that when VNS devices were implanted in obese miniature pigs, they ate fewer sweet foods and lost weight while those with sham devices got more obese. The device, made by Cyberonics of Houston, was cleared by the FDA in 1997 to treat epilepsy and in 2005 for resistant depression, but insurance coverage is still minimal.
In Deep Brain Stimulation (DBS), a pair of electrodes is implanted in the brain and are connected by wires to a pair of pulsing devices in the chest. The electrodes emit a sort of jamming signal to brain circuits thought to be involved in depression. Some 60,000 patients worldwide use DBS to treat Parkinson's disease, a brain disorder that impairs motor skills. But with depression, researchers aren't yet sure where the target area should be.
Both VNS and DBS run some surgical risks, including infection and stroke. Some Parkinson's disease patients with DBS have also become manic and gone on gambling sprees.
Many other technologies are also being investigated—including Magnetic Seizure Therapy, which uses magnets to create more controlled, localized types of seizures and Transcranial Pulsed Ultrasound, which could let doctors focus energy deep into brain circuits without the risk of implanting electrodes. Still other researchers are using optogenetics, quick bursts of colored light, to study how brain cells communicate with each other.
Meanwhile, another older technology is getting new attention. Cranial Electrotherapy Stimulation (CES), which sends very weak microcurrent into the brain, was widely used in Russia in the 1940s as a sleep aid. Several battery-powered CES devices won FDA clearance to treat depression, anxiety and insomnia in the 1980s and 1990s, largely because they were similar to other grandfathered devices, and some have been quietly selling to home users ever since. Electromedical Products International Inc. has been selling its Alpha-Stim devices for both pain relief and anxiety and depression since 1981. Many users are military veterans.
Last fall, a newcomer in the field, Fisher Wallace Laboratories, launched a YouTube campaign lampooning the side effects of anti-depressants and promoting its cranial stimulator as an alternative. Powered by two AA batteries, the device was sends 1 milliampere of alternating current—1/1,000th the voltage used in ECT—through a patient's head via small, wet pads placed at the temples. The company recommends using the device 20 minutes once or twice a day for 30 to 45 days, and several times a week afterward.
The company, founded by electronics entrepreneur Charles Avery Fisher and Martin Wallace in 2007, says the device works by boosting endorphins, serotonin and dopamine and reducing cortisol
Does it work? Columbia University psychiatrist Richard P. Brown says he has used the device with 400 severely depressed patients and that more than 70% find relief—about twice the rate of anti-depressants. "I'm seeing some patients smile for the first time in 20 years," says Dr. Brown, who, like other doctors interviewed for this column, has no financial ties to the company.
Other neuroscientists are wary. "In my assessment of the literature, the level of evidence to support those kinds of claims is not sufficient at this point," says Dr. George.
Dr. Mayberg adds, "It's not a great idea to be exposing your brain to electricity of any type without medical supervision."
Much of the clinical data supporting CES devices is outdated; a few small placebo-controlled trials of the Fisher Wallace device are planned at Harvard, Columbia and the University of Toledo.
"I think a lot of people who use it will tell you it can be very helpful," says Andres San Martin, a Columbia psycho-pharmacologist who says about 50 of his patients use the device, along with antidepressants. Some use it just half the year for Seasonal Affective Disorder, and some have found it helpful in quitting smoking. "But I am looking forward to the double-blind placebo-controlled trials," he says.