Drugs found to be more effective against depression than electric current

A new study questions the efficacy of treatments for depression based on stimulating brain areas with low-intensity electric current. The technique, known as transcranial direct-current stimulation (tDCS), was considered a promising alternative to treatment with antidepressant drugs.

In the new study, researchers at the University of São Paulo's teaching hospital (HU-USP) and the Psychiatry Institute of Hospital das Clínicas (HC-FMUSP-IP), the largest general hospital in Brazil, describe a trial in which they found tDCS to be less effective than escitalopram, an anti-depressant.

The team of researchers led by André Brunoni, a professor in the Psychiatry Department of the University of São Paulo's Medical School (FMUSP) and director of HC-FMUSP-IP's Interdisciplinary Neuromodulation Service, randomly divided 245 patients with depression into three groups.

One group was treated with tDCS plus oral placebo, the second received sham tDCS treatment plus the anti-depressant, and the third received sham tDCS treatment plus oral placebo.

The tDCS treatment was administered in 30-minute sessions for 15 consecutive weekdays, followed by seven once-weekly sessions. Escitalopram was administered at a dose of 10 mg per day for three weeks and 20 mg per day for another seven weeks.

"We defined non-inferiority of stimulation compared with medication as at least 50%, meaning that tDCS would have to be at least 50% as effective as the anti-depressant, but this wasn't the case," Brunoni said.

"We found that treatment with tDCS was not half as effective as treatment with escitalopram and concluded that transcranial stimulation cannot be recommended as first-line therapy. The anti-depressant is easier to administer and much more effective. On the other hand, tDCS performed better than placebo in our previous studies."

About 12%-14% of the world's population is estimated to suffer from depression, and it is relatively easy to find self-help websites with videos showing how to administer tDCS at home.

Brunoni stressed the importance of not confusing tDCS with other methods such as electroconvulsive therapy (ECT), which involves a far stronger current - typically 800 milliamperes, or 800 times the current used in tDCS - and is designed to produce a controlled seizure. Other differences include the fact that ECT delivers a brief pulse rather than a steady current.