PROJECT SUMMARY Preclinical Alzheimer’s disease clinical trials enroll cognitively normal participants who are willing to undergo disease biomarker testing, learn the results, and take an investigational drug (or placebo) if those results indicate that they are at increased risk for disease. Like traditional trials in Alzheimer’s disease dementia, these trials require participants to enroll with a study partner, a person who can attend visits with the participant and report about any changes in the participant’s cognitive or functional ability. These trials face difficult recruitment, especially in enrolling samples representative of the nation’s diverse population. Understanding potential differential attitudes toward the unique requirements in preclinical AD trials will be essential to instructing inclusive recruitment, enrollment, and conduct of preclinical AD trials. This project will examine potential differential attitudes toward preclinical AD trials among African American/Black, Asian American, Hispanic, and non-Hispanic White older cognitively unimpaired individuals. The project will focus on two key requirements in these trials: biomarker disclosure and the study partner requirement. There is strong rationale to hypothesize that these groups may differ in their attitudes toward these requirements. This includes our previous demonstration of differential attitudes toward the requirements based on whether an individual would enroll with a spouse as a study partner and the enrollment patterns of dyads in the first preclinical AD trial, the Anti-Amyloid treatment in Asymptomatic AD (A4) Study. In A4, 58% of non- Hispanic White participants enrolled with a spouse study partner, compared to 45% for Hispanic, 46% for Asian, and 27% for African American/Black participants. This project will provide critical data toward improving preclinical AD trial protocol designs and requirements, as well as practices in disclosure, to ensure diverse and inclusive recruitment that respects potential cultural differences in attitudes toward the requirements of these important studies.