Adolescents with mood disorders experiencing major depressive episode have poor efficacy of medication treatment. High-Definition Transcranial Direct Current Stimulation (HD-tDCS) has been proven adjuvant efficacy in patients with major depressive episode. However, the optimal evidence-based stimulation parameters have not been clearly defined, which greatly limits the efficacy of HD-tDCS in the treatment of major depressive episode.This trial will compare a novel form of accurate and personalized HD-tDCS treatment protocol guided by neuroimaging biomarkers to the routine stimulation(stimulation target is L-DLPFC, central electrode is anode).The personalized selection of stimulation site, central electrode polarity will be determined by neuroimaging biomarkers. The study aims to propose a novel personalized neuroimaging-guided HD-tDCS strategy, to evaluate the efficacy and safety of the treatment, further to understand the biological mechanism of the personalized HD-tDCS treatment.

Mood disorders, including mainly bipolar disorder (BD) and major depressive disorder (MDD), have become the primary health problem and one of the leading causes of functional disability in adolescents . In China, the incidence of mood disorders such as BD and MDD in adolescence has increased rapidly in recent years. Particularly, patients with mood disorder currently experiencing major depressive episode have high risk of suicide, and pharmacological treatment showed poor efficacy to such depressive patients. Mood disorders with major depressive episode have become one of the major threats to the mental health of adolescents in China. Therefore, it is of great significance to explore a series of early intervention strategies for adolescents with major depressive episode. HD-tDCS is a non-invasive brain stimulation treatment strategy with mild side effects. The set of stimulation parameters often has a vital impact on the final clinical efficacy of HD-tDCS treatment. Several clinical trials have reported the efficacy and safety of HD-tDCS on treatment major depression disorder. However, the evidence-based optimal targets and other stimulation parameters have not been clearly defined, which greatly limits the efficacy of HD-tDCS in the treatment of major depressive episode. To date, there is no large randomized clinical trial (RCT) exploring an optimization of HD-tDCS on adolescents with major depressive episode. This study is a randomized controlled trial aiming at assessing the efficacy and safety of a novel personalized HD-tDCS treatment protocol compared to routine stimulation for major depressive episode in adolescents with mood disorders. Participants will be assigned randomly (1:1) to the personalized HD-tDCS group or the routine HD-tDCS group. Participants will be treated with 20 sessions (2 sessions per day) HD-tDCS treatment. The stimulation parameters of routine HD-tDCS group are: current=2 mA, duration=20 min, stimulation target=L-DLPFC, central electrode=anode. The stimulation parameters of personalized HD-tDCS group are current=2 mA and duration=20 min, while the stimulation target and central electrode polarity are based on neuroimaging biomarkers extracted via machine learning. Participants in both groups will maintain the stable drug regimen during the HD-tDCS trial.