Stereotactic Radiotherapy Treatment for Treatment-Resistant Depression

Inclusion Criteria: * Outpatients or inpatients aged 18 to 50 years (inclusive), regardless of gender. * Meet the diagnostic criteria for Major Depressive Disorder (MDD), recurrent, without psychotic features, as defined by The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5). * Documented treatment-resistant depression, defined as a lack of clinically meaningful response (less than 50% improvement in depressive symptoms) to at least two adequate antidepressant trials during the current episode, as recorded by the Massachusetts General Hospital Antidepressant Treatment Response Questionnaire (MGH-ATRQ). An adequate trial requires sufficient dosage (within the recommended therapeutic range) and duration (at least 6 weeks). The current episode must involve at least one treatment failure. * A Hamilton Depression Rating Scale 17-item (HAMD-17) total score of ≥ 20 at both the screening and baseline visits. * The subject agrees to maintain their existing baseline antidepressant therapy regimen unchanged throughout the study period. * The patient and their legal guardian understand and voluntarily agree to participate in this study, are capable of adhering to the treatment protocol, and provide written informed consent. Exclusion Criteria: * A current or prior diagnosis of any other DSM-5 mental disorder, including but not limited to: neurodevelopmental disorders, bipolar and related disorders, obsessive-compulsive and related disorders, schizophrenia …