The purpose of this study is to determine how well a blood test can detect amyloid beta, a protein involved in Alzheimer's disease. Participants will be asked to complete an initial blood collection and cognitive testing, and a subset of participants will be asked to complete a larger blood collection, amyloid PET imaging, and an MRI.

Alzheimer's disease is the most common cause of dementia and currently has no disease-modifying treatments or simple, accurate diagnostic tests. Amyloid beta builds up in the brain and forms plaques in people with Alzheimer's disease, and the buildup of this protein is found decades before symptoms of dementia begin. A blood test may be able to quickly and inexpensively screen people for Alzheimer's disease clinical trials and eventually diagnose Alzheimer's disease in the clinic.

Inclusion Criteria:

1. At least 60 years of age

Exclusion Criteria:

1. Unable to perform one or more activities of daily living (eating, bathing, dressing, ambulating, toileting) due to cognitive impairment or dependent on others due to cognitive impairment.
2. Body weight of <100 pounds
3. Active infectious disease (e.g., HIV, hepatitis B, hepatitis C)
4. Bleeding disorder
5. Taking an experimental drug for AD
6. Blood donation in the last two months
7. Blood transfusion in the last three months
8. On hospice

Participants will be recruited from clinics and communities throughout the greater St. Louis metropolitan area.

Individual participant data which documents, supports and validates research findings will be made available after the main findings from the final research data set have been accepted for publication. Such research data will be de-identified to prevent the disclosure of personal identifiers.

Data will be available immediately following publication with no end date.

Qualified researchers who provide a methodologically sound proposal will be able to access the data to achieve aims in the approved proposal. Proposals should be directed to batemanr@wustl.edu. To gain access, requestors will need to sign a data access agreement.