Adverse childhood experiences (ACEs) are one of the causes of depression in middle-aged and older adults, but the combined effects of ACEs, cognitive function and ability to perform activities of daily living (ADL) on depression have not been fully explored.This study was based on data from 4 waves (2013, 2014, 2015 and 2018) of data from the China Health and Retirement Longitudinal Study, including 10,995 middle-aged and older adults. ACEs were derived from the 2014 self-report life history module. A latent variable growth curve model was used to assess the mediating effect of cognitive function and ability to perform ADL in the relationship between ACEs and depression.ACEs were significantly associated with lower initial cognitive status (β = -0.156, P < .001), worse ability to perform ADL (β = 0.051, P < .001) and higher severity of depression (β = 0.228, P < .001). The results of mediation analysis indicated that the association between ACEs and the intercept of depression was partly mediated by the initial level of cognitive function and ADL, and the association between ACEs and the slope of depression was total mediated by cognitive (intercept and slope) and ADL (intercept and slope).ACEs were associated with higher severity of depression in part due to lower cognitive function and worse ability to perform ADL. Interventions that focus on reducing ACEs and improving cognitive level and ability to perform ADL may effectively reduce the incidence of depression among middle-aged and older individuals.Copyright © 2024. Published by Elsevier B.V.