Efficacy and Safety of tACS for Depression: a Multicenter RCT Study

Transcranial alternating current stimulation (tACS) is a promising non-invasive technique for major depression, because of its advantage of lower risks and expenses compared to other therapies such as deep brain stimulation, electroconvulsive therapy, and repetitive transcranial magnetic stimulation. Randomized controlled trials (RCTs) of depression treated by tACS have been conducted but provided limited and incongruous results. We designed a multi-center RCT to evaluate the efficacy and safety of tACS for depression.

Eligible participants will be patients diagnosed with depression (HDRS-17≥8), aged 18 to 65, and without other conditions that could interfere with the study. A total of 72 participants will be recruited from 4 clinic centers. Participants will be randomized 1:1 to active tACS or sham stimulation group. The study staff and the participants are blinded to the randomization results. Stimulating electrodes will be placed on the scalp corresponding to bilateral dorsolateral prefrontal cortex (DLPFC) using frequency of 10Hz and amplitude of 1.5 to 2.0 mA. The intervention will last for 4 weeks, containing 20 40-minute sessions in total. Another 4-week observation will be followed by the end of the intervention. Participants will receive assessments at baseline, 2 weeks, 4 weeks, 6 weeks, and 8 weeks after the study begins. Psychological scales are used for the evaluation of their mental and quality of life. Besides, electroencephalogram (EEG) recording and magnetic resonance imaging (MRI) scans will also be performed to quantitatively measure the neural activities as well as the functional connectivity changes within the depression-related circuits.