The goal of this project is to quantify the relative effectiveness of aerobic exercise monitored by smart wristbands in assisting the treatment of depression and improving cognitive function. It aims to explore the mechanisms through which aerobic exercise exerts its effects using imaging genetics and other methods, and to identify suitable populations for exercise, ultimately providing personalized clinical exercise prescriptions. This study will intervene from a behavioral perspective and also seeks to motivate participants to change and improve their physical activity habits.

Inclusion Criteria:

1. Aged 18-45 years (including 18 and 45), no gender restriction;
2. Meets the diagnostic criteria for depressive disorders according to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-V);
3. Outpatients or inpatients; Hamilton Depression Rating Scale 17-item (HAMD-17) score ≥ 14; Mood Disorder Questionnaire (MDQ) screening negative to exclude bipolar disorder patients; and Clinical Global Impressions-Severity (CGI-S) score ≥ 4;
4. Maintained on antidepressant treatment for at least 4 weeks or not using antidepressant treatment;
5. Written informed consent obtained from the patient.

Exclusion Criteria:

1. Diagnosed with other mental disorders, including schizophrenia, bipolar disorder, alcohol or substance abuse/dependence, eating disorders, etc.;
2. Individuals with intellectual disabilities or who are unable to cooperate for other reasons, or those lacking or having incomplete civil capacity during the onset of illness;
3. Suffering from neurological or organic brain diseases (such as stroke, cerebral hemorrhage, brain tumors, Parkinson's disease, epilepsy, etc.) and a history of severe traumatic brain injury;
4. Suffering from conditions with high exercise risk, such as hypertension or heart disease;
5. Currently undergoing systematic psychological therapy;
6. In the 3-minute step test, males with a recovery heart rate more than131 and females with a recovery heart rate more than 140;
7. Physically restricted individuals unable to participate in physical exercise;
8. Physical Activity Readiness Questionnaire (PAR-Q) score ≥ 2;
9. Pregnant women or individuals with contraindications to MRI examinations;
10. Individuals with severe suicidal tendencies or at risk of harming others.