Major depressive disorder (MDD) is a prevalent mental illness characterised by influencing the health and quality of life of patients，often manifesting in individuals under the age of 18. It has been wildly confirmed that acupuncture alone or in combination with the applicable adjuvant therapy for MDD can not only relieve patients' physical symptoms, but also enhance sleep quality. Intradermal acupuncture, as an acceptable and long-lasting treatment modality, is the focus of this research. This study was conducted to investigate the efficacy of intradermal acupuncture in the treatment of MDD.