Disparities in the Life Course Origins of Cognitive Decline Project Summary/Abstract A growing number of studies reveal that Black (African American) and Hispanic Americans have markedly higher prevalence and incidence of cognitive impairment and dementia than do White (non-Hispanic) Americans.1-3 Despite the evidence, the reasons for the disparities remain a subject of continuing debate. In addition, the relatively modest literature on longitudinal studies of cognitive decline have been mixed, with some studies demonstrating equivalent or slower rates of decline,4-6 and others reporting faster rates of decline for minorities compared to older Whites.7-9 Discrepancies in these findings may be due to differences in the life course origins of cognitive decline. The purpose of this project is to explicate the life course origins of cognitive decline and the resources that mediate those relationships. We investigate the influence of life course stressors on the risk of cognitive decline in later life among Black, White, and Hispanic Americans as well as the resources that reduce the risk of cognitive decline in these three groups. We focus on cognitive decline—an important hallmark of the development of Alzheimer’s Disease and Related Disorders (ADRD)—and seek to identify resources that empower diverse groups of Americans to reduce the risk of early cognitive decline. We hypothesize that chronic inflammation is a mechanism by which stressors accumulated over the life course exact a toll on cognitive functioning but that this is remediable via social, psychological, and community resources. Although most of the extant research on the topic examines White adults, the present study investigates whether the mechanisms vary for Black, White, and Hispanic Americans. Resources such as social relationships and lifestyle factors vary across racial and ethnic communities, suggesting the value of investigating distinct mechanisms for amelioration. We use eight waves of data from the Health and Retirement Study (HRS), organized in two studies, to test hypotheses. Study 1 examines data from 9,872 adults (age 65+) in 2004 who are re-interviewed biennially, providing 14 years of observation. Study 2 uses information from 9,879 adults (age 65+) in 2010, incorporating rich data from the Life History Surveys launched in 2015 and 2017. There are three specific aims: 1. To examine disparities in the relationships between life course stressors and cognitive decline—an important hallmark of the risk of ADRD. 2. To identify whether chronic inflammation is a mechanism for how life course stressors influence cognitive decline among Black, White, and Hispanic older adults. 3. To determine if the life course resources that potentially mediate the relationships between life course stressors and cognitive decline are distinct for Black, White, and Hispanic older adults.