Delayed effect of bifrontal transcranial direct current stimulation in patients with treatment-resistant depression: a pilot study.

Background: Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique, which has yielded promising results in treating major depressive disorder. However, its effect on treatment-resistant depression remains to be determined. Meanwhile, as an emerging treatment option, patients' acceptability of tDCS is worthy of attention.