Can a wearable helmet treat depression at home?

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

1\. Inclusion Criteria 1. Demographics Aged 18-65 years, any gender. Minimum education: primary school completion (≥6 years of formal education). 2. Diagnostic and Severity Requirements Meet DSM-5 criteria for Major Depressive Disorder (MDD). Current moderate-to-severe depressive episode, defined by Hamilton Depression Rating Scale 17-item (HAMD-17) score ≥18 . 3. Pharmacological Stability Stable antidepressant regimen for ≥4 weeks prior to enrollment, restricted to SSRIs (Selective Serotonin Reuptake Inhibitors). Treatment-naïve patients permitted if no psychotropic medications used within the prior 4 weeks. Mandatory maintenance of the same regimen throughout the study and post-treatment follow-up. 4. Technical Feasibility Medically eligible for both structural MRI and resting-state functional MRI (fMRI) examinations. 2\. Exclusion Criteria 1. Psychiatric Comorbidities Any concurrent psychiatric diagnosis (e.g., autism spectrum disorder, severe cognitive impairment, epilepsy, mania, psychosis) . 2. Neurological Structural Abnormalities Structural brain lesions increasing seizure risk or disrupting neural connectivity (e.g., brain tumors, history of stroke). 3. Systemic Medical Conditions Unstable cardiovascular, respiratory, hepatic, renal diseases, or active malignancies. 4. Contraindications to Procedures TMS contraindications: Metallic implants, pacemakers, history of epilepsy. MRI contraindications: Ferromagnetic implants, claustrophobia requiring sedation. 5. Recent Neuromodulation Therapies Prior ECT (Electroconvulsive Therapy) or rTMS (repetitive Transcranial Magnetic Stimulation) within 3 months. History of neurosurgical interventions for depression (e.g., deep brain stimulation). 6）Special Populations Pregnancy, lactation, or planning pregnancy during the study. 7）Medication Instability Planned adjustments to pharmacotherapy during the study period. 3. Withdrawal and Discontinuation Criteria 1. Participant-Initiated Withdrawal Voluntary withdrawal: Participant withdraws consent (e.g., refusal to risk assignment to sham stimulation group). 2. Investigator-Initiated Withdrawal Non-compliance with inclusion criteria: Post-randomization discovery of ineligibility (e.g., symptom remission, medication non-adherence). Serious Adverse Events (SAEs): TMS-related SAEs (e.g., seizure, intractable headache, exacerbated suicidality). 3. Study Discontinuation Prespecified Efficacy Stoppage: Interim analysis at n=30/group showing superiority of active intervention (Cohen's d \>0.8) . Safety-Driven Discontinuation: Unacceptable risk profile (e.g., recurrent SAEs such as seizures or suicidality). Loss to Follow-Up: Trial termination if attrition rate exceeds pre-specified thresholds compromising statistical power (e.g., \>20% dropout).