BackgroundDepression presents a significant risk to the physical and mental health of the elderly. The relationship between sleep and depressive symptoms has become a major research focus. However， previous research findings on this relationship have yielded inconsistent conclusions. ObjectiveTo explore the relationship between sleep duration and depressive symptoms in the elderly， in order to provide insights into the prevention of depressive symptoms and delaying their progression in the elderly. MethodsData analysis involved 8 210 adults aged 60 years or older， utilizing data from the 2018 China Health and Retirement Longitudinal Study （CHARLS） survey. Participants were categorized into two groups those with depressive symptoms and those without- based on the Center for Epidemiologic Studies Depression-10 Scale （CESD-10） criteria. Logistic regression and restricted cubic spline models were used to analyze the association between sleep duration and depressive symptoms. ResultsThe 318 people with depressive symptoms were detected among the 8 210 elderly participants， with an average sleep duration of （6.14±2.05） hours per night. Restricted cubic spline models showed a non-linear association between sleep duration and depressive symptoms （χ²=412.670，P<0.01）. After adjusting for confounding factors， compared to the elderly with a sleep duration 7~7.9 hours， the risk of depressive symptoms in the elderly was 2.971 times higher （95% CI： 2.560~3.449， P<0.01） in those with a sleep duration <6 hours， 1.372 times higher （95% CI： 1.161~1.621， P<0.01） in those with 6~6.9 hours， and 1 185 times higher （95% CI： 1.009~1.393， P<0.05） in those with ≥8 hours. Subgroup analysis showed no correlation between sleep duration ≥8 hours and the risk of depressive symptoms across genders and the 60~69 age group （P>0.05）. ConclusionThere was an approximately nonlinear association between sleep duration and depressive symptoms， with differences by gender and age.［Funded by Sichuan Applied Psychology Research Center， Chengdu Medical College （number， CSXL-22226）］