Multiple trajectories of depressive symptoms among Chinese in middle and late life: Characterization and risk factors

Depressive symptoms, which are continuously changing, are an essential manifestation of depression and can increase the risk of mental disorders and other diseases. Because the causes and cures for depression have not yet been identified, finding the characteristics, and risk factors of depressive symptom trajectories can help us identify at-risk populations early and reduce the related public disease burden.Herein we aimed to figure out the specific manifestations of depressive symptom trajectories among Chinese adults, explore the risk profiles of trajectory groups with higher depression burdens, and test the longitudinal associations between blood biomarkers with depressive symptoms.Trajectories of participants' depressive symptoms measured by the Center for Epidemiologic Studies Depression scores were modeled with growth mixture models from 2011 to 2018. Multinomial logistic models tested associations of baseline covariates with trajectories. Generalized estimating equations were used to explore the longitudinal associations between blood data and depressive symptoms in two waves from 2011 to 2015.Among the sample of 5,641 individuals aged 40 or over, four heterogeneous depressive symptom trajectories were defined: stable-low, high-decrease, stable-high, and low-increase. At baseline, demographic factors and health statuses such as gender, education, income, and self-reported health status were associated with trajectories. A significant association was found between high-density lipoprotein and depressive symptoms.These findings provide clues for predicting and identifying adults with elevated depression burdens in middle and late life and may facilitate the development of targeted preventive strategies for this population.