Stimulating the brain with a weak electrical current could effectively treat depression, claim scientists.
Researchers from the University of New South Wales (UNSW) and the Black Dog Institute have carried out the largest and most definitive study of transcranial Direct Current Stimulation (tDCS) and found up to half of depressed participants experienced substantial relief after the treatment.
A non-invasive form of brain stimulation, tDCS passes a weak depolarising electrical current into the front of the brain through electrodes on the scalp. Patients remain awake and alert during the procedure, the British Journal of Psychiatry reported.
"We are excited about these results. This is the largest randomised controlled trial of transcranial direct current stimulation ever undertaken and, while the results need to be replicated, they confirm previous reports of significant anti-depressant effects," said trial leader, Colleen Loo, professor from UNSW's School of Psychiatry.
The trial saw 64 depressed participants who had not benefited from at least two other depression treatments receive active or sham tDCS for 20 minutes every day for up to six weeks, according to a university statement.
"Most of the people who went into this trial had tried at least two other anti-depressant treatments and got nowhere. So the results are far more significant than they might initially appear - we weren't dealing with people who were easy to treat," Loo said.
Significantly, results after six weeks were better than at three weeks, suggesting the treatment is best applied over an extended period. Participants who improved during the trial were offered follow up weekly 'booster' treatments, with about 85 percent showing no relapse after three months.
"These results demonstrate that multiple tDCS sessions are safe and not associated with any adverse cognitive outcomes over time," Professor Loo said, adding tDCS is simple and cost effective to deliver, requiring a short visit to a clinic.
The study also turned up additional unexpected physical and mental benefits, including improved attention and information processing.
"One participant with a long-standing reading problem said his reading had improved after the trial and others commented that they were able to think more clearly," Loo said.
"Another participant with chronic neck pain reported that the pain had disappeared during the trial. We think that is because tDCS actually changes the brain's perception of pain," he added.