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.
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."