common complaints. Though there is a small risk of seizure,
it’s reportedly comparable to the seizure risk associated with
antidepressant medications. Compared to ECT, Gray says,
“TMS is a walk in the park.”
But like antidepressant medication and ECT, it’s not entirely
clear how TMS is acting on the brain. “The theory is that when
this stimulation occurs in the left frontal brain, it spreads to
the underlying deeper areas of the brain that are involved
in regulation of mood. When we do it over and over again,
it normalizes the neuronal circuits involved in depression,”
says Ananda Pandurangi, MD, a psychiatrist at the Virginia
Commonwealth University School of Medicine.
Like ECT, TMS appears to reset the system. But instead
of jump-starting the entire brain, as ECT does, the magnetic
therapy is much more targeted, says Megan Schabbing, MD,
a psychiatrist at OhioHealth Riverside Methodist Hospital
who treated Gray with TMS. “That’s undoubtedly why it’s so
well tolerated,” she says, “but this treatment provides a novel
approach to the transformation of neural networks.”
Mark George, MD, a neurologist/psychiatrist at the Medical
University of South Carolina and editor of the journal Brain
Stimulation, has been exploring the use of TMS for depression
since the early 1990s. At that time, he says, most neurologists
believed brain stimulation was only successful if it induced a
seizure, as in ECT.
But George believed that the gentler electric currents
generated by TMS could also be effective if they were delivered
repeatedly. Small changes add up, he says. Repeated exercise can
strengthen a weak muscle. And in depression, psychotherapy
can be an effective treatment over time. “You can exercise brain
circuits by retraining how you think,” George says. “We know
repeated minor changes to the system can get the system better.”
George was the co-chair of a multisite, randomized clinical
trial of TMS sponsored by the National Institute of Mental
Health. The study enrolled patients with treatment-resistant
major depressive disorder between 2004 and 2009. After three
weeks of either active TMS or a sham treatment, all patients
were offered an additional three weeks of guaranteed TMS.
Those who received TMS were four times as likely to achieve
remission as compared with patients who received a sham
treatment, the researchers found (Archives of General Psychiatry,
2010). The results were fairly modest, however — about a 30
percent remission rate for TMS at the end of the full six weeks,
compared with perhaps 60 percent for ECT, George says.
Yet it now seems that TMS may be more effective than the
initial trials suggested. Linda Carpenter, MD, a psychiatrist at
Brown University School of Medicine, and colleagues studied
TMS as it’s used in the real world. Across 42 TMS clinics in the
United States, they found that 58 percent of patients showed
improvement, including 37 percent who achieved full remission
(Depression and Anxiety, 2012).
Anecdotally, many practitioners appear to be pleasantly
surprised by the treatment’s success. While the NIH-sponsored
trial found about two in 10 patients experienced remission
following TMS, George, Pandurangi, and Schabbing all say
they’ve seen higher remission rates among the patients they’ve
treated. “It has really exceeded my expectations,” Schabbing says.
The strict protocols in the clinical trials probably account for
some of the difference. Trial participants were required to stop
taking medications during the course of TMS treatment. They
could continue their psychotherapy, but they couldn’t increase
the frequency of their sessions.
Patients receiving TMS in the real world have many
more options, says Pandurangi. They can continue taking
medications to which they may have had a partial response,
and they can see therapists whenever they’d like. Those options
appear to improve patient outcomes. “We mix and match
anything and everything we have to make the patient feel
better,” he says.
Everything’s a question
While TMS shows promise, it’s certainly no miracle cure.
Some of the patients who responded positively to TMS have
experienced remissions lasting months or even years, but
follow-up booster sessions every few weeks or months may help
prevent a relapse.
About six months after her incredible improvement in 2007,
Gray says, her depression began to resurface. She underwent a
second course, this time at a clinic in Vancouver, Canada. While
she felt better, her improvement was more modest the second
Gray had paid out of pocket for the pricey therapy and was
quickly burning through her retirement savings. She couldn’t
afford another round, even after her depression resurfaced
months later. “So I puttered along until a few years ago, when I
had another deep depression,” she says.
By then the treatment had been approved by the FDA. Still,
it took Gray multiple applications over several years before her
insurance company agreed to cover the treatment. She finally
underwent a third course of TMS in 2014. “I feel pretty good,”
she says. “I’ve had two pretty bad pieces of news in the last
couple weeks and I didn’t crumble.”
Now Gray is planning to have a maintenance course of TMS
every month or so, in hopes that it will keep her depression
at bay. She’s still not sure if her insurance will pay for those
booster sessions — and that’s not the only thing that remains
unclear about maintenance TMS.
French researchers recently reported that patients who