The association between pulmonary function and depression in middle-aged and elderly people in China: The role of cognitive ability and sleep time

•High baseline pulmonary function is independently associated with a lower incidence of depression in middle-aged and older Chinese, partly mediated by cognitive abilities.•Pulmonary function and sleep time have synergy with the effects of depression.•It is necessary to take measures to prevent and control the risk of depression in potentially susceptible individuals with poor pulmonary function, poor cognitive ability, and abnormal sleep schedules.