Objective:To explore the relationship between sleep duration and depressive symptoms in middle-aged and elderly people.Methods:A total of 11 931 middle-aged and elderly people aged ≥55 years who participated in the baseline survey of the "Community Cohort Study of Specialized Nervous System Diseases" in China from 2018 to 2019 were selected to obtain basic information about their lifestyle, food intake frequency, disease history, sleep duration. The body height and weight were measured, and body mass index (BMI) were calculated. The subjects with depressive symptoms were screened with the Geriatric Depression Scale (GDS-30). Restricted cubic spline model and multivariate logistic regression model were used to analyze the relationship between sleep duration and depressive symptoms.Results:Among the middle-aged and elderly people aged ≥55 years, 17.79% reported sleep duration less than 7 hours, 16.84% reported that their sleep duration ≥9 hours, and the detection rate of depression symptoms was 7.95%. After adjusting for factors such as region, age, gender, the restricted cubic spline results showed the U-shaped relationship between sleep duration and the risk for depressive symptoms, the results of multivariate logistic regression analysis showed that the risk for depressive symptom in middle-aged and elderly people aged ≥55 years with sleep duration ≤5 hours, 6 hours, and ≥9 hours were 1.749(95% CI:1.279-2.392), 1.284(95% CI:1.021-1.615) and 1.260(95% CI:1.033-1.538) times higher compared with the counterparts with sleep duration 7-8 hours, the risk for depressive symptom in women with sleep duration ≤5 hours, 6 hours and ≥9 hours were 2.115 (95% CI:1.473-3.038), 1.605(95% CI:1.213-2.123) and 1.313(95% CI:1.011-1.705) times higher, respectively, compared with counterparts with sleep duration 7-8 hours, the risk for depressive symptoms in 55-64-year-old middle-aged and elderly people with sleep duration ≤5 hours and ≥9 hours were 1.806 (95% CI:1.014-3.217) and 1.478 (95% CI:1.060-2.061) times higher compared with counterparts with sleep duration 7-8 hours, and the risk for depressive symptoms in elderly people aged 65-74 years with sleep duration ≤5 hours was 2.112 (95% CI:1.327-3.361)times higher compared with counterparts with sleep duration 7-8 hours, the differences were all significant ( P<0.05). There was no statistically significant association between sleep duration and depressive symptoms in men and in elderly people aged ≥75 years ( P>0.05). Conclusion:Insufficient or prolonged sleep was independently associated with depressive symptoms in middle-aged and elderly people, showing a U-shaped relationship, especially in women and in middle-aged and elderly people aged 55-64 years.