This is an observational study that will serially collect 10 plasma samples over the course of 9 weeks from the same individuals to assess fluctuations in blood biomarker results.

Blood biomarkers offer a less invasive and cheaper method for identifying Alzheimer's disease (AD)-related changes. Already, blood biomarkers for AD are being adopted by clinical practice and their use will only expand in coming years. However, blood biomarkers are susceptible to fluctuations not yet well characterized. Such fluctuations, although rarely observed in current research settings, may influence the biological evaluation of dementia once implemented into routine settings. The study at present aims to identify how blood biomarkers fluctuate over a short period of time in the same individual and assess drivers of these fluctuations.

Inclusion Criteria:

• able and wiling to provide informed consent
• Aged 50-80 years old at the time of signing study consent; participants aged 50-59 years will be no more than 20% of the total study population
• Has normal cognition or mild impairment at screening MoCA by a score of greater than or equal to 18; participants with a Montreal Cognitive Assessment (MoCA Test) score between 18-25 will be no more than 20% of the total study population
• able and wiling to fully comply with study procedures defined in the protocol
• Written and spoken fluency in English

Exclusion Criteria:

• Plans to begin any new treatment or is having surgery during the 9-week draw timeframe
• Currently enrolled in a clinical trial using an investigational drug

Arizona residents

study dataset and biological samples will be shared with qualified investigators

Data will be shared within 12 months after study completion