Treating people with depression using weak electrical currents passed into the brain through a headband may help relieve some of their symptoms when combined with an antidepressant, a new study suggests.
Researchers found that after six weeks of treatment with a combination of brain stimulation and sertraline, marketed as Zoloft, nearly two-thirds of depressed participants got significantly better.
But by itself, brain stimulation was no better than medication.
"In the field of depression, it's important to know about treatment options, and medications alone don't work for everyone," said Dr. Sarah Lisanby, a psychiatrist who studies brain stimulation at Duke University in Durham, North Carolina.
"Now there's a broadened array of new, device-based therapies that allow us to affect brain function in less invasive ways," including transcranial direct current stimulation, or tDCS, added Lisanby, who wasn't part of the new research team.
No tDCS devices, including the one used in the new study, are currently approved by the U.S. Food and Drug Administration for use on the brain.
But older types of non-invasive brain stimulation are approved and becoming established treatment options for depression, researchers noted.
For the study, Dr. Felipe Fregni from the Harvard Medical School in Boston and Brazilian colleagues randomly assigned 120 people in Brazil with moderate or severe depression to one of four treatments: tDCS and sertraline, tDCS and a placebo drug, sham stimulation and sertraline or sham stimulation and a placebo.
Electrical current therapy was given for 30 minutes at a time over 12 total sessions.
At the beginning of the study, participants in each of the four groups had an average depression score between 30 and 31 on a 0-to-60 scale, where a higher score indicates worse depression.
After six weeks, people in the combined stimulation and sertraline group saw their depression drop to a score of 13, on average, compared to 25 among people who received both fake treatments.
Data on side effects suggested tDCS had no effect on cognition, researchers said. Skin redness was more common with the real device than the sham stimulator.
And there were five episodes of mania among people who got the combined treatment, even though the researchers had screened out anyone with bipolar disorder - which typically includes periods of depression alternating with mania.
The drug alone and electrical stimulation alone were similarly effective at easing depression symptoms, Fregni's team noted Wednesday in JAMA Psychiatry.
However, the dose of sertraline used - 50 milligrams per day - might have been too low to help most people, Lisanby and another psychiatrist, Dr. Philip Janicak, told Reuters Health.
Janicak, from Rush University Medical Center in Chicago and not involved in the study, said "the question is still out" as to whether this type of stimulation can help people with depression.
"tDCS could very well be an effective treatment," he said. But, "at this point I would never recommend it, based on the evidence that's currently available."
The new study was funded by the Sao Paulo Research Foundation.
Because the tDCS device, marketed as Chattanooga Ionto, has not been approved as a depression treatment, it's hard to say how much it would cost in the U.S., Lisanby noted. She said it should be "relatively cheap and affordable," given that it's small, portable and powered with 9-volt batteries.