Participants and Procedure
MDD, Depressive Disorder, depressive symptoms
CHRONIC DISEASE, DISORDERS, RECRUITMENT
All participants were recruited from the Department of Depressive Disorder of Shenzhen Kangning Hospital and the Department of Psychiatry of Shenzhen Nanshan Center for Chronic Disease Control between August and December 2021.The inclusion criteria of this study were as follows: (1) age 18-60 years; (2) meeting the criteria for MDD in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-V); (3) a score of more than 5 on the Patient Health Questionnaire-9 (PHQ-9), indicating the presence of at least mild depressive symptoms [Psychiatrists visited outpatients to identify potential participants for our study. Trained researchers performed structured diagnostic interviews, which consisted of the MINI, with potential participants to assess eligibility for enrollment in our study. Then, researchers obtained informed consent from all eligible participants and guided them through the online baseline assessment. Random assignment of all participants was performed by a computer randomization program before recruitment. Participants were randomly assigned to the ICBT group or the WLC group. It was not possible for participants or study researchers to be blinded to the treatment allocation owing to the nature of the intervention.