“The basics of TMS treatment are simple,” says Dr. Mark George, who performed research for more than a decade that led to its approval for treatment-resistant depression in 2008. “You have a patient who is awake and alert, sitting in a chair that’s kind of like a dentist’s chair. We place an electromagnet on the scalp, over a part of their brain that we think is dysfunctional in the disease.” In the protocol approved by the FDA, Dr. George chose an area corresponding to a portion of the left prefrontal cortex, high on the forehead above the left eye. This area remains the focus of transcranial magnetic stimulation (TMS) treatments today.

Stimulation is applied repetitively: on and off in spurts for 4 seconds, then 25 seconds off before repeating, over a total of 37 minutes and delivering a total of 3,000 pulses. (Hence the treatment’s technical name, rTMS, for repetitive TMS). “During those 37 minutes, patients are alert, there’s no IV, they can do anything they want before or afterward—there are no restrictions on activity or diet,” says Dr. George.

And there are very few side effects. Most common is a mild headache, typically relieved with aspirin. As for impact, “After the first treatment, the patient usually doesn’t feel any different. But if you treat over several weeks, gradually the symptoms of the depression begin to fade away” in patients who do respond. The FDA-approved treatment is once a day, five times a week for 6 weeks. “So that’s 30 sessions, and then we do what’s called a taper, where we give three treatments one week, and two the next, and then one. We keep our fingers crossed and hope to find that the depression has gone away.”

Dr. George says that effectiveness usually follows “a rule of thirds.” About one-third of treatment-resistant depressed people treated with TMS have a remission; there are no depression symptoms left after the taper period. In another third there is not a remission but instead a “response,” meaning symptoms are cut at least by half. In the final third of patients, there is no response.

“Fortunately, no one seems to get worse with the treatment,” Dr. George says. “Unlike with electroconvulsive therapy (ECT), where we worry about a problem with memory, there are no adverse cognitive effects with TMS at all—it’s quite benign in that way. There are no drug interactions, so it’s good for patients who are already on medications of various kinds.”

Dr. Mark George presents What’s New with TMS for Depression and Other Brain Diseases: 

For those who are helped by TMS, how long can they expect the benefits to last?

“It varies from patient to patient,” Dr. George says. “Some people never need TMS again—they’re out of their depressed episode and they do fine. Others require tune-ups. Good studies have shown that if we swoop in quickly when people start to relapse, we can get them out of the depression very quickly. Instead of 6 weeks of treatment, we might be able to get them well again in 2 or 3 weeks. With only a few exceptions, if you responded in your initial course, you will re-respond if you go back in. It doesn’t seem that patients build up a tolerance with this technology.”

Over the long-term, “some patients require one or two treatments every couple of weeks to maintain their remission. We have some patients who have done that for up to a decade now and it seems to work quite well. Most of these people are also on [antidepressant] medications, but somehow with TMS they’re able to get a quality of life that they were not before.”

Dr. George says that he continues to get calls from patients across the country, asking to come to South Carolina in order to be treated by him. “I say, ‘No, your doctor down there is just as good at TMS and it’s much less stress and strain on you. You can sleep in your own bed and you can hug your dog, and that’s better for your depression.’ The treatment has been successfully standardized—there’s nothing special about the technique, when properly applied.”

— Written By Peter Tarr

Click here to read the Brain & Behavior Magazine's March 2019 issue

Read more about Transcranial Magnetic Stimulation here.