Feasibility, Safety, and Preliminary Clinical Efficacy of Magnetic Resonance Imaging-guided Repetitive Transcranial Magnetic Stimulation (rTMS) in Adolescents With Depression: A Randomized, Double-Blind, Controlled Pilot Study

Inclusion Criteria: 1. Age 12 - 18 2. Diagnosis of major depressive disorder (MDD) according to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), confirmed through the Kiddie Schedule for Affective Disorders and Schizophrenia - Present and Lifetime version (K-SADS-PL), currently in a depressive episode 3. Score≥40 on the CDRS-R 4. Stable pharmacological treatment: At least 4 weeks of stable psychiatric medication use prior to enrollment, with continuation of the same psychiatric medication regimen throughout the study. Exclusion Criteria: 1. Psychiatric comorbidities other than anxiety disorders 2. Depression with psychotic symptoms 3. Young Mania Rating Scale (YMRS) score \>13 4. A history of neurological disorders (e.g., epilepsy, brain injury) or severe somatic diseases (e.g., thyroid disorders, lupus, diabetes, pulmonary, hepatic, or renal impairment, major trauma) 5. Patients currently using anticonvulsants or high-dose benzodiazepines 6. A history of electroconvulsive therapy (ECT), transcranial magnetic stimulation (TMS), transcranial direct current stimulation (tDCS), transcranial alternating current stimulation (tACS), or other neuromodulation treatments 7. A history of alcohol or substance abuse or dependence 8. Women who are pregnant or breastfeeding 9. Current high suicide risk 10. Potential complicating factors related to transcranial magnetic stimulation, such as scalp conditions or perforations that may affect magnetic field delivery 11. Contraindications to MRI