This project analyzes whether the COVID-19 pandemic increased ADRD prevalence, accelerated the progression of cognitive decline among those with pre-existing ADRD, or otherwise changed the trajectory of population-level cognitive decline. We first characterize changes in ADRD prevalence since the onset of the pandemic, and whether these changes in ADRD prevalence also vary by race, ethnicity, and socioeconomic status. Second, we explore the clinical, setting-of-care, and contextual factors that may have contributed to these changes in prevalence. We will explore the roles of individual-level influences, such as COVID-19 related hospitalization, long covid/brain fog symptoms, or COVID-19 vaccinations; and community-level influences, such as hospital bed shortages, economic conditions, median income and poverty rates, health uninsurance rates, regional healthcare resources, and other measures of community vulnerability.