Efficacy, Safety, and Acceptability of Internet-based Cognitive Behavioral Therapy

Prior treatment

• Patients who have received other antidepressant treatments within 3 months prior to enrollment, including Chinese herbal medicine, modified electroconvulsive therapy, transcranial magnetic stimulation, biofeedback therapy, light therapy, acupuncture, and other physical or systematic psychological treatments
• Patients who explicitly express unwillingness to participate in psychological therapy or believe psychological therapy is ineffective
• Patients who have participated in or are currently participating in drug clinical trials within 3 months prior to screening, or in other device clinical trials within 1 month prior to screening

Other illness

• Current clinical diagnosis meeting DSM-5 criteria for psychiatric disorders other than Major Depressive Disorder (confirmed by M.I.N.I.7.0.2)
• History of alcohol and drug dependence
• Other conditions deemed unsuitable for enrollment by the investigator

Lab values

• Current serious physical disease, thyroid disease (thyroid stimulating hormone (TSH) exceeding the upper limit of normal at screening), or patients considered by investigators to have hypothyroidism or hyperthyroidism (at the investigator's discretion, laboratory tests meeting exclusion criteria may be rechecked once within the screening period)

Other

• Treatment-resistant depression (defined as patients who failed to respond to adequate doses and duration (at least 4 weeks at maximum recommended dose) of 2 or more antidepressants with different chemical structures)
• Pregnant or lactating women, or men or women planning pregnancy during the clinical trial period
• Obvious suicidal attempt or behavior, with a score ≥4 on item 10 "Suicidal Thoughts" of the MADRS scale

• Voluntary participation in the trial with signed informed consent
• Age 18-60 years (inclusive), any gender
• Clinical diagnosis of Major Depressive Disorder (MDD) according to the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5) criteria, confirmed by the Mini-International Neuropsychiatric Interview (M.I.N.I.7.0.2), with either single episode or recurrent episodes without psychotic features
• Montgomery-Asberg Depression Rating Scale (MADRS) score ≥18 and \<30 at screening
• No antidepressant medication within 2 weeks prior to screening (6 weeks for fluoxetine), and assessed by the investigator as able to maintain without antidepressant medication during the trial period
• Education level of primary school or above, able to understand the content of assessment scales, and proficient in using smartphones