Efficacy and Safety Assessment of Temporal Interference Stimulation to Improve Bipolar Depression

Inclusion Criteria: * right-handed, and have completed nine years of compulsory education; * Meet the diagnostic criteria for bipolar depression in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5); * ≥18 points on the Hamilton Depression Inventory (HAMD- 17); * ≤8 points on the Young's Mania Rating Scale (YMRS); * Subjects who have not been treated with psychiatric medication, or those who have been treated with medication are required to undergo medication washout within 2 weeks before randomization; * Subjects/legal guardians are willing to cooperate with the treatment and sign an informed consent form after they have fully understood the Temporal Interference Stimulation (TI). Exclusion Criteria: * Contraindications to magnetic resonance scanning (MRI) or time-interference stimulation (TI), such as the presence of metallic or electronic devices in the body (intracranial metallic foreign bodies, cochlear implants, pacemakers and stents, and other metallic foreign bodies); * Prior or current electroconvulsive therapy (ECT), modified electroconvulsive therapy (MECT), transcranial magnetic stimulation (TMS), transcranial direct current therapy (tDCS), transcranial alternating current stimulation (tACS), or other neurostimulation; * Pregnant and lactating women, and women of childbearing age with a positive urine pregnancy; * Possesses a diagnosis of another major psychiatric disorder that has been assessed by the study investigator as a major disorder that results in more impairment than a diagnosis of bipolar disorder; * Co-morbid other psychiatric disorders, including obsessive-compulsive disorder, personality disorders, anxiety spectrum disorders, mental retardation, substance dependence (abuse), etc.; Has active suicidal ideation (≥ 4 points on item 10 of the MADRS); * Risk of serious injury to self or others; * History of serious physical illness or disease that may affect the central nervous system; * Risk of neurologic disorders or seizures, such as previous craniosynostosis, cranial trauma, abnormal electroencephalograms, magnetic resonance evidence of structural abnormalities of the brain, or family history of epilepsy.