Changes since 2020 in the Long-Term Trends in Cognitive Health, Dementia, and Mortality among Older Adults: Quantifying the Impact of Health shocks and Social Disruptions - PROJECT SUMMARY Although the prevalence of Alzheimer’s disease and related dementias (ADRD) has been decreasing, health shocks and disruptions to social interactions in 2020 and 2021 may have halted or reversed that trend. This project will quantify the effects of these shocks and of attendant public health and social measures on the cognitive status, mortality, and well-being of persons living with ADRD and of the older population in general. Persons living with dementia were especially at risk from the widespread health and social changes after 2020. Both those living in nursing homes and those living at home experienced disruptions to their daily personal care, and to their needed health care. Further, those initially not living with dementia may have experienced accelerated cognitive decline because of the shocks, disruptions of daily routines, social isolation and stress. Subpopulations by socioeconomic status, race and ethnicity were likely impacted unequally. This project has three specific aims. The first is to use a new and updated model of cognition to estimate trends in ADRD prevalence, incidence, and mortality prior to 2020. We will use data from the Health and Retirement Study (HRS), a large, nationally representative, longitudinal survey of the U.S. population over age 50. The HRS has a wide range of information on cognitive abilities, mortality, dementia risks, and physical and mental health, but only a subsample of the HRS has a clinical assessment of dementia, those enrolled in the Aging, Demographic, and Memory Study (ADAMS). In prior research, we used ADAMS to develop a model of the probability of dementia to estimate the cognitive status of the entire HRS sample. In this work, we will expand this model to estimate dementia incidence and mortality as well. We will incorporate recently released data from the Harmonized Cognitive Assessment Protocol, further increasing precision so as to permit the study of changes in ADRD since 2020 in subpopulations, such as by marital and socioeconomic status, and by race and ethnicity. Second, we will document changes in mortality, well-being, use of formal and informal care, and other outcomes. We will incorporate variation in state policies to assess their effect on individual outcomes. We will compare these effects among those who were living with dementia prior to 2020 to those whose cognitive function was normal. We will use innovative models and data from various HRS special supplements to estimate these effects with precision. Third, we will estimate the incidence of dementia and dementia mortality from 2020 through 2026, and find the extent to which trends in incidence and mortality changed. We will perform similar assessments on trends in well-being. We will assess whether ADRD incidence differed by individual characteristics, such as geographic location, race, socioeconomic status, and living arrangements. The developed cognition measures will be made publicly available to enhance future research.