PROJECT SUMMARY Despite advances in biomarkers, the accuracy of the diagnosis of ADRD in everyday clinical practice remains inadequate, particularly for health disparities populations. This research program addresses this challenge by validating promising, widely accessible and inexpensive clinical and plasma-based biomarkers in diverse populations in an academic setting and in real-world clinical practice. Our over-arching goal is to reimagine approaches to the diagnosis of ADRD using scalable precision medicine tools. The proposal synergizes the research programs of co-PIs Dr. Gil Rabinovici, a behavioral neurologist and leader in brain imaging and biomarkers, and Dr. Kate Possin, a neuropsychologist and leader in innovation of tablet-based cognitive assessments and dementia care models. We will recruit 400 participants from the UCSF Alzheimer’s Disease Research Center (ADRC), which includes large, heterogeneous, deeply phenotyped clinical cohorts (ranging from cognitively unimpaired to dementia) with a large Latino/Hispanic component; and 750 participants from the New IDEAS study, which is evaluating the clinical utility of amyloid PET in Medicare beneficiaries with MCI or dementia and emphasizes recruitment of Black/African American and Latino/Hispanic patients. With Collaborator Dr. Peggye Dilworth-Anderson, novel enrollment approaches that attend to cultural nuances, provider workflows, and meaningful incentives will help set the standard for inclusive research. All participants will undergo a brief battery of domain-specific cognitive tests, and surveys of social determinants of health (SDH), cognitive and functional symptoms, and caregiver factors. Blood based biomarkers of amyloid, tau and neurodegeneration will be measured in 1,000 participants with co-investigator Dr. Sid O’Bryant. We will identify vulnerability factors and care needs that will inform future diagnostic care models. All participants will undergo amyloid PET, and UCSF ADRC participants will additionally undergo tau PET and MRI. We will identify the clinical measures and blood-based biomarkers that best predict molecular pathology. We will develop classifiers that consider patient factors, SDH, cognition, caregiver factors, and blood-based biomarkers to predict amyloid and tau PET findings, necessity for PET imaging and health outcomes. We will mentor and support junior and early stage-investigators throughout the project. This project will address ADRD Research Implementation Milestone 9.L “Improving differential diagnosis of symptomatic cognitive impairment,” while also advancing additional key Milestones related to racial/ethnic diversity and blood-based biomarkers. This work will ready the field for inclusive identification of appropriate candidates for disease modifying therapies.