Inclusion Criteria:  Out-patients; Men or women aged between 16 and 50, with junior high school education or above; According to medical history, patients should be diagnosed with major depressive episode by two or above psychiatric doctors based on ICD-10 criteria; According to assessment, patients should meet the DSM-5 criteria for MDD when in past episodes; Patients received stable ant-depression medication treatment for at least 8 weeks before enrolment; 17-item HAMD total score ≤ 7; Willing to participate in this study, and sign an informed consent.  Exclusion Criteria:  HCL-32 total score < 12; Diagnosed with bipolar disorder; Suffering from some serious physical diseases (e.g. moderate or severe brain injury, central nervous system diseases, or other unstable physical condition affecting the whole body) adversely affects the performance on neuropsychological test or rating scales; Received ECT in the past 6 months.