A Life-course Approach to Depression among Middle-aged and Elderly in India: Evidence from the Longitudinal Aging Study in India - 2018-2019

Abstract Background Depression is a major public health concern in India contributing significantly to morbidity, dysfunction, reduced quality of life, and economic loss. Evidence from previous studies suggest that risk to developing mental illness begins in the early years of life. Thus, we aim to examine the effect of early life conditions-childhood health status and childhood socioeconomic status on depression later in life and the mediating role of other risk factors along life-course- education, current economic status, chronic physical condition(s), and health behaviours - in the effect of early life conditions on depression later in life. Methods We used data from Longitudinal Aging Study in India (2018–2019) to find the association between the possible risk factors, including early life conditions, and depression later in life using logistic regression. The factors that were found to be significantly associated with depression later in life were used in the second step of mediation analysing using Karlson-Holm-Breen method, to examine the role of mediators in the effect of early life conditions on depression later in life. Results Childhood health, childhood socioeconomic status, education, current economic status, chronic physical condition(s), and tobacco use were found to be associated with depression later in life. Childhood health directly influences the occurrence of depression later in life and its effect is not mediated by risk factors along life course. On the contrary, the effect of childhood socioeconomic status on depression later in life is at least partially mediated by risk factors along life course- education, current economic status, chronic physical condition(s), experience of depression and tobacco use. The greatest contribution to this mediation is by discrimination, followed by tobacco use and education. Chronic physical condition is also a major contributor but it acts as a suppressor. Furthermore, the childhood health also mediates the influence of early life socioeconomic status on depression later in life. Conclusions Our findings demonstrate the pertinence of childhood health in reducing the burden of depression later in life. It also underscores the importance of focussing on risk factors along life course- discrimination, tobacco use, and education, health behaviours- for individuals who belonged to families having low socioeconomic status during childhood, and initiatives to prevent chronic physical conditions particularly among those who did not have adverse socio economic status during childhood in order to reduce the burden of depression among middle-aged and elderly population in India.