More specifically, the goals of this study are to 1) explore the potential biomarkers for Major Depressive Disorder by comparing MDD patients and healthy controls; 2) investigate the biochemical indicators for subtypes of MDD through long-term cohort follow-up studies; 3) investigate the differences and similarities among different types of MDD patients in terms of cognitive functions, biological tests, as well as neuroimaging data; 4) evaluate and analyze the prognosis of patients according to the baseline level, and search for the biomarkers regarding MDD treatment response to guide the clinical treatment and intervention of patients with MDD; 5) Through the long-term follow-up study, the behavioural and biochemical indicators of the patients with MDD were collected, the differences between the indicators before and after remission were examined, and the state and quality of the pathophysiological indicators of the patients with MDD were investigated.
This experiment intends to explore the differences among various types of depression, as well as the differences between healthy subjects and depressed patients, and find possible biological markers from the severity of symptoms, social function and cognitive function of depressed patients, combined with EEG characteristics, biological test indicators (blood, faeces, hair, etc.) and functional magnetic resonance imaging data.~To explore the changes in clinical symptoms, cognitive and social functions, and biological indicators of various types of patients before and after treatment, to provide references for the prognosis of various types, and to predict the future development of the disease according to the baseline indicators of patients; According to the above aspects, this experiment can follow up the patients with depression, track their disease development, and study the potential biological changes in the early stage of the disease, which has the potential to reveal the pathogenesis and provide guidance for the early diagnosis and intervention of depression.