Using weak electrical currents passed into the brain through a headband may help relieve depression symptoms for some patients when combined with an antidepressant, according to a U.S. and Brazilian study.
Researchers writing in JAMA Psychiatry found that after six weeks of treatment with a combination of brain stimulation - known as transcranial direct current stimulation or tDCS - and sertraline, marketed as Zoloft, nearly two-thirds of depressed participants got significantly better.
"In major depressive disorder, the combination of transcranial direct current stimulation and sertraline increases the efficacy of each treatment," wrote lead researcher Felipe Fregni from the Harvard Medical School.
For the study, Fregni and Brazilian colleagues randomly assigned 120 people in Brazil with moderate to severe depression to one of four treatments: brain stimulation and sertraline, brain stimulation and a placebo drug, sham stimulation and sertraline, or sham stimulation and a placebo.
No tDCS devices, including the one used in the study, are 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.
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 meant 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.
"In the field of depression, it's important to know about treatment options, and medications alone don't work for everyone," said Sarah Lisanby, a psychiatrist who studies brain stimulation at Duke University.
"Now there's a broadened array of new, device-based therapies that allow us to affect brain function in less invasive ways."
Data on side effects suggested that the tDCS stimulation had no effect on cognition, researchers said. Skin redness was more common with the real device than the sham stimulator.
The drug alone and electrical stimulation alone were similarly effective at easing depression symptoms, Fregni's team said. However, the dose of sertraline used - 50 milligrams per day - might have been too low to help most people, psychiatrists said.
Philip Janicek, from Rush University Medical Center in Chicago, said it was still unclear whether this type of stimulation can help people with depression.
"tDCS could very well be an effective treatment," he said, though he added that at this point he would not recommend it based on the current evidence.