Objective and subjective childhood socioeconomic disadvantage and incident depression in adulthood: a longitudinal analysis in the Sister Study.

Understanding of the role of objective versus subjective childhood socioeconomic disadvantage (SD) in depression onset in adulthood among women, independent of later life SD, and across birth cohorts, is limited. We examined the association between objective (i.e., household education level) and subjective (i.e., rank of family income and report of not enough food to eat) SD during childhood and diagnosis of clinical depression after age 30 among 47,055 women in the Sister Study. We used Cox proportional hazard models adjusting for women's race/ethnicity, childhood household composition, mother's age at her birth adulthood educational attainment, and calendar year of birth. Analyses were repeated stratified by 10-year birth group. A total of 8036 (17.1%) women were diagnosed with clinical depression over a mean follow-up of 24.0 (± 9.9) years. Those reporting being poor (versus well-off) or not having enough food to eat in childhood had a 1.28 (95% confidence interval (CI) 1.13, 1.44) and 1.30 (95% CI 1.21, 1.41) times higher rate of depression diagnosis, respectively, with consistent associations observed across birth year groups. An inverse association between low household education level and incident depression was observed at baseline (i.e., age 30) becoming positive over time in the total sample but only among women born between 1935-1954 in analyses stratified by 10-year birth group. Our findings suggest that subjective SD in childhood is a largely consistent predictor of depression onset among women in adulthood whereas the effects of household education level in childhood may vary across women born into different birth cohorts, and for some, across the lifecourse.