One multi-center, randomized controlled clinical trial is designed to examine whether transcutaneous electrical cranial-auricular acupoint stimulation (TECAS) is non-inferior to the antidepressant drug (Escitalopram) in treating mild-to-moderate depression, to evaluate the depressive subtypes who are suitable for the TECAS treatment. To achieve this objective, 470 patients with mild-to-moderate depression will be recruited and assigned to receive TECAS treatment (n =235) or Escitalopram (n =235, 10-20mg/day, q.d.) for 8 weeks. The primary outcome is the Montgomery-Åsberg Depression Rating Scale (MADRS); other outcomes include the17-item Hamilton Depression Scale (HAMD-17), the Hamilton Anxiety Rating Scale (HAMA), Pittsburgh sleep quality index (PSQI), the Short Form 36 Health Survey and TCM diagnosis of depression. In addition, the safety index will be measured throughout the whole study.

Depression is a common and costly disorder with high prevalence rate and high suicide rate. Antidepressants are the first-line treatments for depression. However, approximately 50% to 60% of the patients have not achieved adequate response following antidepressant treatment.

A large body of evidence well confirms that electro-acupuncture is effective in improving depression and reducing anti-depressant treatment-caused side effects, including pain, nausea, dizziness, fatigue, anxiety and sleep disturbance.

Based on the combination of ancient and modern literature and famous traditional Chinese medicine practitioners' experience, the Evidence-based Guidelines of Clinical Practice with Acupuncture and Moxibustion-Depression (ZJ/TE003-2014) recommended Baihui (DU20) and Yintang (DU29) as main acupoints in treating patients with depression via electro-acupuncture.

Our research team have completed a series of clinical trials, including electrical stimulation on cranial and auricular acupoints for treating depression, postpartum depression, post-stroke depression, and depression with somatic pain. These studies found that cranial-auricular acupoint stimulation, as well as transcutaneous electrical stimulation, can improve depressive symptoms and accompanying symptoms in patients with depression significantly.

Unlike traditional acupuncture, transcutaneous electrical stimulation does not need needles to penetrate the skin. It places electrodes on the skin of the corresponding acupoints. In this way, traumatic pain and fear of acupuncture can be avoided. And it is more easily accepted for patients and more convenient for clinical operation. Therefore, the investigators plan to build a novel transcutaneous electrical stimulation therapy--Transcutaneous electrical cranial-auricular acupoint stimulation (TECAS).

In the proposed study, a combination of transcutaneous electrical cranial and transcutaneous electrical auricular acupoint stimulation will be employed to treat patients with mild-to-moderate depression compared with antidepressant Escitalopram, to confirm the clinical effectiveness of TECAS in mild-to-moderate depression.

Inclusion Criteria:

1. Primary diagnosis as mild to moderate depression；
2. Aged 18-70；
3. A score of MADRS ≥12 and <30 without suicide risk;
4. Participants to give consent and to cooperate with the treatment and data collection;

Exclusion Criteria:

1. Pregnant；
2. Patients with severe diseases of heart, brain, liver, kidney or hematopoietic system, patients with acute diseases, infectious diseases and malignant tumours;
3. Patients who are unable to stop taking relevant drugs as required during the trial; (any other drug or non-drug treatment that affects depressive symptoms, including Chinese medicine, western medicine, and physical therapies et al.)
4. Patients with any history of psychosis or mania;
5. Patients with cognitive disorders or personality disorders;
6. Patients with serious suicidal ideation or behaviours.