Progression of depressive symptoms after early exposure to famine: The China Health and Retirement Longitudinal Study

The effect of early exposure to famine on progression of depressive symptoms has not been studied and the Chinese Famine offers a unique opportunity to explore this association with its long duration and widespread influence.To investigate the longitudinal association of early famine exposure with subsequent depressive symptoms and whether there existed a critical exposure period.Data from the China Health and Retirement Longitudinal Study (CHARLS) were analysed. Famine exposure was evaluated retrospectively in 2014 and severe famine exposure was defined as starvation to death of family members. Depressive symptoms were assessed prospectively from wave 1 (2011-2012) to wave 4 (2018) using the 10-item Center for Epidemiological Studies Depression Scale (CES-D). Linear mixed model and Cox proportional hazards model were applied to evaluate associations of famine exposure with progression or occurrence of depressive symptoms.A total of 7053 participants were included. Compared with no famine exposure, severe famine exposure was associated with a faster growth in CES-D score (0.169 point/year, 95 % CI 0.035 to 0.304, P = 0.013) and an elevated risk of occurrence of depressive symptoms (HR 1.360, 95 % CI 1.069 to 1.729, P = 0.012). Further analysis revealed that famine exposure during middle childhood was associated with a faster growth in CES-D score (0.404 point/year, 95 % CI 0.164 to 0.644, P = 0.001).This is an observational study therefore causal relationship cannot be concluded.Early exposure to severe famine was associated with aggravation of depressive symptoms. Middle childhood might be a critical time window for depression prevention.