May 4, 2010 -- A controversial new treatment for depression, rTMS, helps some patients, a rigorous government-funded study finds.
The treatment is called repetitive transcranial magnetic stimulation. It's basically an electromagnet. When applied to the skull just behind the left forehead, the device induces a tiny electric current in a part of the brain linked to depression.
Because the device carries little risk, the FDA in October 2008 cleared the device for treatment of major clinical depression in adults who got no relief from first-line antidepressant treatment. But questions remained about whether the device really helps depression.
Remission of Depression Achieved in Some
The biggest hurdle to studying the device was finding an inactive placebo to compare it with. In earlier studies, patients and researchers had no trouble telling the real device from a sham. That's important because the placebo effect -- the tendency of some people to get better from fake treatment -- is strong in clinical trials of depression treatments.
After much struggle, the researchers used earphones and electrodes to mimic the actual sound, sight, and feel of a real rTMS session, says study researcher Sarah Lisanby, MD, chief of the brain stimulation and therapeutic modulation division at Columbia University and the New York State Psychiatric Institute.
Lisanby and colleagues signed up 190 people who had failed to get relief from at least one antidepressant medication; many had tried several different treatments. They received either rTMS or the sham treatment for three weeks.
The result: 14% of those treated with rTMS had remission of their depression, compared with only 5% of those getting the sham treatment.
Those whose depression did not get better after three weeks entered a continuation trial in which the sham treatment was discontinued and everyone got rTMS. Thirty percent of the patients in this continuation study had remission of their depression.
"The effect sizes we report with rTMS are about on par with what you see with antidepressant medications," Lisanby tells WebMD. "The difference is that to get into our study, people had to have failed to have responded to a medication. And studies show that with previous failure to respond to an antidepressant, the rate of success for a second antidepressant is lower."
rTMS Treatment Needs Refinement
What does all this mean for people looking for relief from depression?
For starters, it means that people have a new treatment option, says Matthew Rudorfer, MD, associate director for treatment research at the National Institute of Mental Health (NIMH).
Rudorfer notes that in the study, people were more likely to benefit from rTMS if they received the treatment before trying (and failing to get relief from) more than one antidepressant medication.
"It is looking as if rTMS would be more effective earlier in the treatment course rather than later," Rudorfer tells WebMD. "More work needs to be done to find the right niche for this. We are very interested in personalizing treatment for depression, and this fits that theme. For a small but significant proportion of people who have not responded to medication -- one, probably, and not a whole series of drugs -- this could be a viable alternative."
Rudorfer suggests that in real-life clinical practice, doctors probably will combine rTMS treatment with antidepressant treatment.
The study showed that rTMS does not induce seizures and appears to be free of major adverse effects.
Lisanby notes that researchers are still working to optimize rTMS by finding the best treatment dose and duration, as well as by working to pinpoint the region of the brain where stimulation will have the greatest effect.
Although the study was funded by the NIMH without industry support, Lisanby reports receiving research grants with several companies involved with rTMS including Neuronetics Inc. Columbia University has a patent on TMS technology in Lisanby's name. Lisanby's research colleagues also disclose receiving grants, fees, and/or advisory board work for such firms.
The rTMS devices used in the study were the FDA-cleared NeuroStar devices made by Neuronetics. This device was selected in a competitive bidding process.
Lisanby and colleagues report their findings in the May issue of Archives of General Psychiatry.