The psychological and social impact of the pandemic have been severe and likely will have significant mental effects over the long term. There is also emerging evidence that suggests that COVID-19 may have direct effects on the brain or trigger immune responses that have additional adverse consequences on brain function and mental health in patients with COVID-19. COVID-19 has disproportionately impacted older adults, with those 65 years and older at heightened risk of severe illness. In fact, most older adults with COVID-19 survive initial infection and enter a clinical recovery phase for months or longer, which is often marked by persistent symptoms and adverse health outcomes. Thus, there is an urgent need to understand the neuropsychiatric sequelae of COVID-19, especially in older adults. The primary goal of the proposed research is to determine whether COVID-19 is associated with increased incidence of dementia (Alzheimer’s disease and related dementias) and new or reemergence of psychiatric disorders in a national sample of patients 65 years and older, with complete outcome ascertainment from Veterans Health Administration and Medicare data. The secondary aim is to examine risk factors associated with development of these neuropsychiatric disorders (i.e., Alzheimer’s disease and related dementias [AD/ADRD], mood disorders, anxiety disorders, and psychosis) among older adults with history of COVID-19. The intent of the current proposal isn’t to be deterministic about the mechanisms of these associations, but to move the field forward informing current knowledge gaps about COVID-19 as a risk factor for neuropsychiatric disorders in late life. The current proposal will substantiate the early reports of neuropsychiatric effects from COVID-19 in small studies in a large geographically and racially diverse national sample using comprehensive data sources and advanced statistical methods and will improve our understanding of whether COVID-19 is a risk factor for the development of AD/ADRD and psychiatric disorders (Aim 1). Furthermore, this study will identify the baseline risk factors for development of AD/ADRD and psychiatric disorders among individuals with COVID-19 (Aim 2) and determine whether certain acute and post- acute symptoms are indicative of a higher risk for developing AD/ADRD (Aim 3). Given that over 79 million Americans have been diagnosed with COVID-19, even small increases in risk of AD/ADRD and psychiatric disorders may have significant consequences for patients, their caregivers, and the U.S. health care system. It is likely that the proposed research will help to identify individuals that may be at higher risk and support engagement in early intervention strategies that will lead to mitigation of AD and related diseases and late-life mental health disorders.