Worries over seizures
The most common side effects of rTMS include transient headache, scalp discomfort and the sensation that something is tapping on the patient's head in time with pulses during sessions. (In contrast, electroshock, which even Neuronetics says is more effective than rTMS, could cause memory problems and diminished mental acuity.)
The side effect that draws the most concern is rare but serious: grand mal seizures. They trigger loss of consciousness and violent muscle contractions. "Seizures do occur, and they should not be brushed off," George says. The rate of seizures is on par with medication therapy, but hard data is difficult to find, he says, adding that no organization tallies these events globally. A show-of-hands survey during an rTMS conference in Italy this year indicated that some are underreporting seizures, according to George, a vocal proponent of rTMS. Still, he estimates that there have been fewer than 50 rTMS-initiated seizures worldwide since the mid-1980s.
Risks can be reduced by carefully vetting rTMS candidates according to the FDA-approved guidelines, says Jon Nilsen, who operates a NeuroStar at the McGrath Clinic in Orland Park, Ill. Nilsen also acknowledges that patients on antidepressants, which themselves carry a risk of seizure, as well as those with a history of seizures are more likely to have an rTMS-related event.
Wassermann says that overly cautious doctors and entrepreneurs are holding back the development of rTMS for depression. He was among the researchers who created laboratory guidelines in 1998 for applying rTMS—guidelines that he says were "cautious" in regard to minimizing the chance of seizures. Those protocols, he says have gone largely unexamined.
"It's asking a lot of a box that you plug into the wall to change your brain and your life" without hobbling its further development with timidity, Wassermann says.
It also asks a lot of people's pocketbooks. The McGrath Clinic charges a discounted rate of $265 per single-day session without insurance, Nilsen says, but it charges $300 to $350 per session if health insurance firms reimburse for treatments. Because insurance coverage for rTMS is spotty, some psychiatrists say they sometimes treat severely impacted patients for free.
As of August 3 Aetna health insurance refused to reimburse for rTMS, which it considers "experimental and investigational". Michigan's Priority Health Insurance Co. covers the initial six-week treatment. Priority, however, does not cover "maintenance" sessions used to prolong remissions and treat relapses, saying the efficacy of these regimens has not been proved.
Psychiatrist Denise Lin says the benefits she has seen in some of her severely depressed patients outweigh the risk of seizure. Lin, founder of Advanced Psychiatric Care of Santa Barbara, Calif., bought a NeuroStar in January.
All five people she has treated with rTMS have reported at least some improvement, Lin says. One patient had been assessed before trying rTMS as very severely depressed based on the widely used Hamilton Depression Rating Scale (HAM-D), a series of multiple-choice questionnaires that clinicians use to rate depression severity. After a six-week course the patient was judged to be in remission and rated "normal" on the HAM-D scale, Lin says.