REVISED PROJECT SUMMARY/ABSTRACT Biomarkers of Alzheimer’s disease (AD) hold immense potential to impact clinical care of patients with cognitive disorders. However, the potential burdens and benefits of AD biomarker testing must be carefully balanced. Several studies of the personal implications of such testing have found that disclosing AD biomarker results does not cause clinical depression, anxiety, or suicidality. Most of this evidence has been derived from samples comprised of highly educated, cognitively healthy, persons who were scanned as part of a research protocol. There is pressing need to move beyond investigations of the psychological safety of disclosing biomarker results to highly selected research participants, to develop an understanding of the full range of burdens and benefits of AD biomarker testing in real-world populations. The proposed study is designed to optimize remote participation for individuals participating in AD biomarker testing in studies and clinics across the country. We will recruit 500 individuals participating in AD biomarker testing to enroll in a 6-month observational study to address the following Specific Aims. Aim 1. Quantify the range and patterns of emotional response to a biomarker-informed cognitive diagnosis, and determine which clinical or demographic factors are associated with specific responses. Aim 2. Characterize the “value of knowing” one’s AD biomarker status among symptomatic patients and their immediate family members. Aim 3. Identify the information and support needs of families receiving biomarker- informed cognitive diagnoses. Our overarching hypothesis is that responses to biomarker-informed ADRD diagnoses are heterogeneous and associated with distinct clinical and sociodemographic factors. This study will advance the field’s understanding of real-world patient and family reactions to biomarker-informed ADRD diagnoses, providing critical information for directing post-diagnostic resources to monitor and support those most in need. Findings will inform best practices in the rapidly evolving state-of-the-art diagnostic evaluation of cognitive impairment.