Effects and mechanism of sleep characteristics on cognitive function in MDD

Depression is a kind of disease with high prevalence and high recurrence rate, which seriously endangers the physical and mental health of all human beings. The World Health Organization says depression will be the second leading cause of disability by 2020. Depression is characterized by severe and / or long-term depression; dysregulation of emotion and motivation; cognitive problems, such as attention and decision-making difficulties; and sleep changes, and has a great risk of suicide. Most patients with depression often have different types of sleep disorders, sleep disorders and cognitive impairment exist in the whole course of depression, and sleep disorders and cognitive symptoms interact. Therefore, understanding the relationship between early sleep characteristics and cognitive impairment should be a priority; in addition, after antidepressant treatment, the changes of subjective and objective sleep characteristics of patients are related to the changes of cognitive dimensions, which are also concerned by clinicians. Therefore, it is necessary to identify the impact of potential early sleep characteristics on cognitive impairment and recovery process of patients with depression To explore the early trigger factors or markers may help clinicians choose or increase prevention and treatment strategies to improve cognitive impairment, improve the prognosis of patients, and reduce the conversion rate and mortality of refractory depression. The main purpose of this study is to explore the relationship between subjective and objective sleep characteristics and cognitive impairment in patients with acute depression, and explore its possible biological mechanism, so as to provide scientific basis for clinicians to improve the diagnosis and treatment of patients with sleep disorders, and to explore the role of intestinal microbiomes in this process.