Clinical Efficacy, Safety, and Applicability of Home-based Bright Light Therapy in Outpatient Adolescents With Major Depressive Disorder

The inclusion and exclusion criteria for MDD patients： 1. inclusion criteria * Meeting DSM-IV diagnostic criteria for a major depressive episode (first-episode or recurrent) , confirmed by two experienced, independent psychiatrists using the Mini International Neuropsychiatric Interview for Children and Adolescents (MINI-Kid); * Aged 13-17 years ; * Medication-naïve or on a stable pharmacological regimen for ≥1 week prior to enrollment; * Baseline Hamilton Depression Rating Scale-17 (HAMD-17) score ≥14; * Minimum of 5 years of formal education, with the ability to complete clinical assessments and comprehend study-related information; * Voluntary participation with written informed consent provided by both participants and their legal guardians. 2. exclusion criteria * Current or past diagnosis of psychiatric disorders other than anxiety or sleep disorders; * History of substance abuse or dependence history (including alcohol, nicotine, or illicit drugs); * Baseline Young Mania Rating Scale (YMRS) total score ≥6; * Received or planned to initiate non-pharmacological systemic interventions within 6 months prior to enrollment or within 1 month after enrollment, including but not limited to: structured psychotherapy (≥1 session/month for \>6 months), physical therapy (e.g., modified electroconvulsive therapy \[MECT\], repetitive transcranial magnetic stimulation \[rTMS\], transcranial direct current stimulation \[tDCS\], or deep brain stimulation \[DBS\]), or exercise therapy ; * Clinician-assessed suicide risk or a HAMD-17 item 3 score ≥3 at the baseline; * Presence of severe systemic or neurological conditions, such as diabetes, hypertension, renal failure, hepatic dysfunction, thyroid disorders, encephalitis, traumatic brain injury, or epilepsy; * Severe retinal pathologies (e.g., retinal detachment, optic atrophy, macular degeneration); or having high myopia (spherical equivalent ≤ -6.00 diopters); * Current use of photosensitizing agents or medications (e.g., chlorpromazine, hypericum extract); * Any other condition deemed inappropriate by the investigators(e.g., cases involving severe sleep phase delays that make morning therapy impossible, or unrecorded photosensitivity). The inclusion and exclusion criteria for Health controls 1. Inclusion criteria * Aged 13-17 years and right-handed; * Minimum of 5 years of formal education, with the ability to complete clinical assessments and comprehend study-related information; * Voluntary participation with written informed consent provided by both participants and their legal guardians. 2. Exclusion criteria * Current or lifetime diagnosis of any psychiatric disorders (e.g., schizophrenia, mood disorders, anxiety disorders) or history of substance/drug abuse or dependence; * First-degree family history of psychiatric disorders; * Presence of severe systemic or neurological disorders, such as diabetes, hypertension, renal failure, hepatic dysfunction, thyroid disorders, encephalitis, traumatic brain injury, or epilepsy; * Any other condition deemed inappropriate by the investigators.