Background: Major depression occurs more frequently among people of lower socioeconomic status (SES) and among females. Although the focus of considerable investigation, the development of SES and sex differences in depression remains to be fully explained. In this study, we test the hypotheses that low childhood SES predicts an increased risk of adult depression and contributes to a higher risk of depression among females.
Methods: Participants were 1132 adult offspring of mothers enrolled in the Providence, Rhode Island site of the US National Collaborative Perinatal Project between 1959 and 1966. Childhood SES, indexed by parental occupation, was assessed at the time of participants' birth and seventh year. A lifetime history and age at onset of major depressive episode were ascertained via structured interviews according to diagnostic criteria. Survival analyses were used to model the likelihood of first depression onset as a function of childhood SES.
Results: Participants from lower SES backgrounds had nearly a twofold increase in risk for major depression compared to those from the highest SES background independent of childhood sociodemographic factors, family history of mental illness, and adult SES. Analyses of sex differences in the effect of childhood SES on adult depression provided modest support for the hypothesis that childhood SES contributes to adult sex differences in depression.
Conclusions: Low SES in childhood is related to a higher risk of major depression in adults. Social inequalities in depression likely originate early in life. Further research is needed to identify the pathways linking childhood conditions to SES differences in the incidence of major depression.