When it comes to treating depression, it’s tough to know what will work for specific people who have the condition.
Antidepressants are commonly prescribed, but between 10 percent and 30 percent of people with major depression who take the medications fail to show improvement.
But now, a new treatment that involves the use of magnetic stimulation to "rewire" parts of the brain has been approved by the Food and Drug Administration (FDA).
It has proven effective in treating people with depression and could potentially be used in other applications, as well.
This treatment, called transcranial magnetic stimulation (TMS), targets specific parts of the brain in a noninvasive way.
“The way that we believe TMS works is as a brain network treatment,” Dr. Andrew Leuchter, a senior research scientist at the Semel Institute for Neuroscience and Human Behavior, and director of the neuromodulation division at the University of California Los Angeles (UCLA) Health, told Healthline.
“As opposed to medications, which kind of work from the bottom up, they work at the level of the nerve cell, and then spread from there,” Leuchter said. “TMS picks specific nodes of a brain network and introduces energy into those.”
The number of clinics offering TMS is growing as the treatment offers an alternative for people who haven’t responded to antidepressants.
A seed of an idea
Leuchter says that TMS has been around as a diagnostic and research tool since the mid-1980s.
“It was in the 90s that people began to realize there are many ways to stimulate the brain,” he said. “Of course, electroconvulsive therapy (ECT) had been around forever. But people thought if you can use electricity to stimulate the brain, how about using electromagnetic energy? Pulsing the brain with an electromagnet to try to achieve the same result, but with a much better side effect profile. People began to experiment with it, discover that, in fact, you can provide very focal brain stimulation that seemed to relieve the symptoms of depression without nearly the side effects of ECT. It was studied for a number of years, and approved by the FDA in 2009.”
A major advantage to TMS when compared with antidepressants is its relative lack of side effects.
“A lot of times, antidepressant medications are used for these different conditions, and they can be helpful,” said Leuchter. “The problem is, with medication you’re commonly dealing with side effects. You’re taking a medication and distributing it throughout the bloodstream, throughout the body. You end up, therefore, with effects on virtually every organ system and in many instances the side effects can be problematic — nausea, weight gain, headache, dizziness, those kinds of things.”
“The nice thing about TMS as a treatment is that you are really applying it directly to a specific part of the brain. It has very, very few side effects. Therefore, we are able to achieve a therapeutic effect for the patient with a much more favorable side effect profile, by targeting the treatment to the precise brain area that we need to hit in order to get the patient some benefit.”
Cost can be an issue
Eight years after its approval by the FDA for depression, TMS is available in every major metropolitan area in the United States.
Leuchter estimated there are currently between 800 and 1,000 TMS devices being used in practices across the country.
“[TMS devices] are still not as widespread as we would like them to be, in order for everybody to have access,” says Leuchter. “The good news in terms of access is that insurance companies are now pretty routinely covering TMS treatment for depression. So it’s something that is more and more widely successful, both because the devices are out there in the community, and because it’s a covered benefit under a lot of insurance plans, including Medicare.”
For those without health benefits, however, the cost can be significant.
While out-of-pocket costs vary by geographic region, a 6- to 9-week treatment of TMS typically costs somewhere in the range of $14,000.
The out-of-pocket costs for uninsured Americans may be higher than the cost of antidepressant medications, but Leuchter says there are a few caveats.
“It is important to bear in mind that TMS generally is performed in patients who have suffered for years with unrelenting depression and have failed to benefit from multiple courses of medication treatment and psychotherapy,” he said.
“There have been a few health economics studies that have looked at the cost effectiveness of TMS treatment — the cost per QALY, or quality-adjusted life year — and have concluded that TMS is a very cost-effective alternative.”
More than just depression
There are more potential applications for TMS treatment on the horizon.
“TMS works for a whole variety of different conditions,” said Leuchter. “Anything where focal brain stimulation might be helpful. So it’s been used with success not just for depression, but for bipolar disorder, for obsessive-compulsive disorder, PTSD too. We’ve used it with some success here at UCLA for the treatment of tinnitus — that’s chronic ringing of the ears. And it also is quite useful for the treatment of chronic pain conditions. So a variety of different applications are in development.”
With Americans spending billions of dollars every year on antidepressants and the country in the midst of an opioid epidemic, TMS offers a possible alternative.
“We’re excited about treatments like TMS that actually can offer a great deal of relief for chronic pain without the side effects of opioids,” said Leuchter. “I think that what we’re going to see going forward is that there will be more and more of those brain stimulation neuromodulation methods that can help reduce pain symptoms with fewer side effects. So we’re very interested in exploring those avenues of research.”