Life course influences on cognitive aging and dementia risk: A mini-forum on the role of socioeconomics,caregiving,and social determinants

Life course social, behavioral, and contextual factors, such as early childhood experiences, employment history, as well as changes in familial structures and roles, play a significant and yet understudied role in the advancement and experience of Alzheimer's disease and related dementias (ADRD). These factors can be particularly consequential in exacerbating disparities in cognitive health outcomes. One of the primary aims of the National Institute of Aging-funded Alzheimer's Disease-Related Resource Centers for Minority Aging Research (AD-RCMAR) is to foster rigorous social and behavioral research that advances knowledge to help eliminate health disparities. To this end, one such AD-RCMAR, the Michigan Center for Contextual Factors in Alzheimer's Disease (MCCFAD), convenes an annual 4-day summer data immersion program that brings together interdisciplinary scientists from across the nation to work on a large nationally representative data set, inclusive of cognitive, epidemiological, economic, and social variables, that addresses novel scientific questions about contextual risk and resilience factors implicated in ADRD. The 2024 Summer Data Immersion focused on using the life history data uniquely available through the Health and Retirement Study (HRS).

The HRS is a nationally representative longitudinal panel study of adults aged 51 plus in the United States that has been conducted since 1990. Information has been collected from respondents, or in some instances proxies, through face-to-face or telephone interviews, internet surveys, and mail-back questionnaires. Sample sizes in any given wave range from 18,000 to 23,000. During the 2024 Summer Data Immersion workshop, research teams led by established and emerging scientists explored how early life psychosocial, socioeconomic, educational, caregiving, and other experiences link to cognitive health and dementia risk in later life. Study findings address the complexities introduced by gender, immigrant, and ethnoracial group identity to risk and resilience factors associated with cognition. Briefly, they reveal that low childhood socioeconomic status is linked to higher dementia risk in later life, and show evidence for how early life adversities, such as parental divorce, are associated with increased loneliness, which accelerates memory decline in older age. The studies also highlight the negative role of weak life course social ties to later-life cognitive outcomes, identify subpopulations of older adults whose cognitive outcomes are subject to the harmful effects of job disruptions related to family caregiving, and clarify how links between age at migration and cognitive health are shaped by country of origin among Hispanic older adults. The research also underscores the negative effects of school segregation on cognition in older Black adults and demonstrates the potential long-term benefits of integrated educational settings.

Overall, findings suggest that interventions targeting social and behavioral experiences earlier in the life course could mitigate cognitive decline. These results highlight the importance of adequate early educational opportunities, caregiving support policies, and effective social integration programs to improve cognitive outcomes and reduce disparities in cognitive aging. We wish to thank the National Institutes of Health, and particularly the National Institute on Aging for funding this work (U01AG009740, P30AG059300), and all the scientists whose work culminated in the following papers.