Magnetic pulses to battle depression
A machine that sends magnetic pulses into a patient’s brain has become the new frontier of depression treatment, promising to ease symptoms for those who have found little relief from medication or talk therapy.
The treatment, known as transcranial magnetic stimulation, or TMS, is part of a wave of technologies that attempt to jolt the brain back to health. In the United States it caught on quickly after the Food and Drug Administration approved its use six years ago; clinics in Australia cover it but in New Zealand it is currently only available in certain academic and tertiary medical centres. (Victoria University in Wellington has a TMS machine).
Though some have questioned the technology’s effectiveness, in the US more insurance companies are starting to cover it, helping with a price tag that can reach US$10,000 for six weeks of treatment.
“What this does is raises (your mood) up to normal,” a 55-year-old woman from Chicago’s western suburbs said after finishing a treatment session at Linden Oaks at Edward in Naperville. “You can operate.”
Stimulative brain therapies have been around for decades, the best known being electroconvulsive therapy, a technique that uses an electric current to cause a seizure. It was portrayed as a mind-erasing menace in the movie One Flew Over the Cuckoo’s Nest, though psychiatrists say the procedure is safe today.
Other methods use implanted devices to send electrical pulses to the vagus nerve — a transmission line that carries messages to the brain’s mood center — or to the brain itself. Some studies have found that these techniques help to elevate the moods of people with severe depression.
Dr. Mark George, a South Carolina psychiatrist who edits the medical journal Brain Stimulation, said TMS produces similar effects without the need for surgery.
A patient sits in a chair that resembles something from a dentist’s office as a device containing the magnetic coil is placed on his head. When it’s activated, George said, magnetic pulses penetrate the skull and stimulate nerve cells — the Linden Oaks patient described the sensation as “having a woodpecker sitting on your head” — provoking a therapeutic response.
George acknowledged that the technology doesn’t work for everyone. Early studies, which relied on subjects who had been taken off their medications, found that only about 15 per cent saw their depressive symptoms go away.
But later research that allowed subjects to stay on their meds, which George called a more true-to-life test, found that 40 per cent had complete relief from their symptoms, while 60 per cent got at least somewhat better.
That’s not as effective as electroconvulsive therapy, which has full remission rates of around 60 per cent, but George said that treatment requires patients to be anesthetised and is known to cause memory and cognitive problems in some.
TMS, by contrast, requires no sedation, and its biggest complication appears to be discomfort where the magnets are placed on the head.
“It’s a highly effective treatment and has only trivial side effects,” said Dr. Jesse Viner, medical director at north suburban Evanston’s Yellowbrick psychiatric health care center. “There’s no persistent adverse effect. You can have a little bit of a headache or facial pain, but that quickly subsides, and in our experience, by the time people have their third or fourth treatment, they’re OK.”
The effectiveness of TMS came into question in 2007 when the FDA was considering its use as a depression treatment. The Washington-based advocacy group Public Citizen, which often tangles with the agency over what it considers lax standards for medical devices, claimed the study the FDA relied on was unreliable.
The data at first showed that TMS was not significantly superior to a “sham treatment” that didn’t subject patients to the magnetic pulses, the group said: Better results from TMS were evident only when some subjects were removed from the trial, and even then the difference was small.
What’s more, the group said, patients receiving TMS knew they were getting something because unlike the sham treatment, the pulses produced a painful sensation.
“Given the small differences we were seeing, that could have been explained by the placebo effect,” said Dr. Michael Carome, director of Public Citizen’s health research group.
Dr. David Brock of Neuronetics, the Pennsylvania-based company that sought FDA approval for its TMS machines, pointed to a rebuttal by the study’s authors that defended their methodology and cited the improvement made by patients who received the treatment. Subsequent research, Brock said, has further demonstrated the effectiveness of the technology.
The FDA decided to allow TMS as a depression treatment, and many Medicare contractors have since covered the service. Though private insurance companies remain split, with companies such as Blue Cross and Blue Shield of Illinois paying for TMS and others declining to do so, more than 100 million people now have coverage for the treatment, Brock said
That has encouraged more health care providers to invest in the machines, which doctors said cost US$75,000 to US$90,000 (NZ$94,000 to $113,000). But Dr. Rad Gharavi, a suburban Oak Park psychiatrist who has offered the service for four years, said insurance problems remain.
Coverage begins only after a patient has failed to get better after trying antidepressants. Gharavi said that can force patients to endure the side effects of medications for months.
“That means we are essentially delaying treatment,” he said. “TMS can literally take away all the symptoms in six weeks.”
It was more complicated than that for the Linden Oaks patient, who has dealt with depression since she was a teenager. She first received the treatment four years ago but comes for follow-up treatments every three months or so when she “can feel the beast creeping up,” she said.
“It’s apparently very individualised,” she said. “There’s been a bit of fine-tuning in terms of knowing when to come back for a booster.”
Dr. Philip Janicak, a psychiatrist who has researched and performed TMS and is now helping Linden Oaks set up its program, said a recent study to which he contributed found that, generally speaking, the effects of the treatment last for a year.
With TMS now firmly established as a depression treatment, Janicak said research is turning to other possible uses, from migraines to Parkinson’s disease to post-traumatic stress disorder.
“I see us really at the opening of this era,” he said. “There’s a lot of things we can do with this technology to help people, and we’re just starting to touch the surface of it with depression.”
-The Chicago Tribune