Modern studies have confirmed that skin temperature changes at acupoints when the body is under pathological conditions. This suggests that changes in the thermal radiation characteristics of acupoints can objectively respond to the symptoms of a disease. In this study, the investigators first evaluated reproducibility of acupoint temperature measurement by IRT. Secondly, the investigators explored the thermal radiation characteristics of MDD-related acupoints, built the diagnostic model for adolescent depression severity and the diagnostic model for MDD in adolescents based on acupoint temperature. Our research findings will provide new ideas, methods and visualisations for early screening, auxiliary diagnosis and condition assessment of MDD in adolescents.

A total of 100 subjects were included, 60 adolescent with MDD (MDD group) and 40 healthy controls (HC group). All subjects accepted IRT detection.The random selection of 30 adolescent with MDD allowed the collection of the bilateral same name acupoint temperatures. Intra- and inter-observer reproducibility for the patients were examined in some randomly selected patients by 2 investigators and 2 investigators both made 2 independent measurements in a week. 30 MDD subjects were detected the bilateral same name acupoint temperatures.

Inclusion Criteria:

Inclusion criteria for the healthy control participants:

• 12years≤ age<18 years;
• SDS score <53;
• Adolescents with normal cognitive function can cooperate with the study;
• Adolescents and guardians agree to the study plan and sign the informed consent form.

Inclusion criteria for the major depression disorder participants:

• 12years≤ age<18 years;
• Self-rating Depression Scale (SDS) score ≥ 53;
• Language, cognition and communication ability are normal;
• Patients and guardians agree to the study plan and sign the informed consent form.

Exclusion Criteria:

Exclusion criteria both for the healthy control participants and major depression disorder participants:

• Severe anxiety, schizophrenia, or other serious mental illnesses;
• There are pigmentation, redness, infection or scarring on the skin at the site of detection;
• Patients with severe systemic diseases and their complications, serious infections, and major diseases of viscera, tissues, and systems;
• Female patients who were pregnant or lactating;
• Female patients who were during, or in proximity (±2 days) to their menstruation or ovulation;
• Patients with a body temperature ≥37.3°C;
• Inability to cooperate during the examination;
• Participating in any other clinical trials.

The diagnostic criteria of MDD were based on criteria proposed by the International Classification of Diseases 10th Edition (ICD-10). Healthy control participants were determined by a recent depression screening report for confirming their mental health conditions.