Past Studies
Thank you for visiting our page highlighting brain health studies that have completed enrollment. Here you will find brief descriptions about the aims of each study and insights we have gained from them so far about healthy aging, memory loss, Alzheimer's disease, and/or related conditions. This page is a testament to the vital role that community members play in research, as your participation helps uncover new knowledge that can improve care, support earlier diagnosis, and improve quality of life for people from all communities.
Alzheimer's Disease Neuroimaging Initiative 4 (ADNI 4)
The primary goal of the Alzheimer’s Disease Neuroimaging Initiative (ADNI) is to explore relationships between clinical, cognitive, imaging, genetic, and biomarker tests to understand the full spectrum of Alzheimer’s disease (AD) from its earliest stage.
Some of the highlights of ADNI to date include:
- Establishing biomarkers for Alzheimer’s disease: ADNI research helped identify key changes in cerebrospinal fluid—specifically low levels of Amyloid beta (Aβ)42 and high levels of tau protein—that signal a high likelihood of Alzheimer’s disease.
- Understanding the progression of Alzheimer’s disease: Using ADNI data, researchers developed a model showing that amyloid changes appear first, followed by other brain changes like accumulation of tau tangles and loss of brain cells, after which the first signs of memory and thinking problems appear.
- Validating PET brain imaging: ADNI helped standardize PET scans that detect amyloid and tau in the brain, improving diagnosis and tracking of Alzheimer’s disease over time.
- Developing blood tests for Alzheimer’s: ADNI studies advanced blood-based markers, like phosphorylated tau (p-tau181) and neurofilament light (NfL), which show promise for early detection, predicting disease course, and monitoring progression.
- Improving clinical trials: ADNI findings have guided smarter trial design, helping researchers choose participants, measure treatment effects, and run more efficient and cost-effective studies.
The most recent cycle (ADNI 4) was designed to engage participants from different at-risk groups to ensure that Alzheimer's research represents all people. Enrollment in ADNI 4 closed to new participants in 2025. Those who are currently enrolled will participate in annual visits over the next several years to ensure these important discoveries are equally valid and meaningful for all people.
START - Synaptic Therapy Alzheimer's Research Trial
The Synaptic Therapy Alzheimer's Research Trial (START) is a clinical trial investigating the safety and efficacy of a new medication in slowing memory loss associated with Alzheimer's disease (AD). The study aims to explore a novel approach to treating AD by protecting the parts of brain cells that communicate with each other (synapses). Enrollment closed in 2025 and participants will be followed for18 months. We look forward to sharing the outcome of this exciting effort once the trial ends and results are published.
Mayo Clinic Study of Aging (MCSA)
The Mayo Clinic Study of Aging (MCSA) was established in 2004 to explore how often biomarkers of dementia (e.g., amyloid, vascular pathology) are present in middle-aged and older adults, to examine if and how these biomarkers predict changes in memory over time, and to understand the factors that raise or lower risk of cognitive decline and dementia.
Some highlights from MCSA include:
- Brain Changes Linked to Aging and Dementia
MCSA participants have helped researchers identify common brain changes that occur with aging, such as protein buildup (amyloid), blood vessel problems, and shrinkage of brain tissue. These findings have been used to create “risk scores” that help predict who may be more likely to develop memory problems or dementia. - Tracking Memory and Thinking Over Time
The study followed people as they aged, showing how some experience normal, gradual changes while others develop mild cognitive impairment (MCI) or dementia. This work has revealed both protective factors (things that may slow decline) and risk factors (things that may speed it up), such as blood vessel health, mood issues, and inflammation. - Building a Shared Research Resource
Through the generosity of MCSA participants who have allowed their data to be shared, Mayo Clinic has been able to create one of the largest publicly available collections of brain scans and clinical data, including nearly 6,000 participants studied over 15 years. This open resource allows scientists around the world to explore questions about aging and dementia. - Insight Into Causes of Alzheimer’s Disease
MCSA findings confirmed that a protein called tau plays a stronger role than amyloid in driving memory loss and decline in Alzheimer’s disease. Both are important, but this discovery is helping guide the development of new treatments.
The Jacksonville arm of the Mayo Clinic Study of Aging (MCSA) is an observational research initiative focused on tracking normal (cognitively healthy) aging in adults aged 45 and older who live in the community and are cognitively normal at baseline. The standout goal of the Jacksonville MCSA cohort is increasing inclusion of Black and Hispanic community members, as these groups are at higher risk of dementia but often underrepresented in research.
- Key Publications
- Mayo Clinic study of thousands of brains reveals tau as driver of Alzheimer's disease.
- Physical Activity and Trajectory of Cognitive Change in Older Persons: Mayo Clinic Study of Aging.
- Predicting the Risk of Mild Cognitive Impairment in the Mayo Clinic Study of Aging
- A Large Public Release of Clinical and Imaging Data from the Mayo Clinic Study of Aging.
MarkVCID
MarkVCID (bioMarkers in Vascular Cognitive Impairment and Dementia) is a collaboration of US medical centers whose mission is to discover and confirm reliable “biomarkers” (measurable signals in the brain or blood) that can identify problems with the small blood vessels of the brain that cause memory and thinking problems (or worsen these problems in people with dementia). Finding these biomarkers will speed up progress in understanding vascular contributions to dementia and opens the door to better prevention and treatment.
We thank the members of the Jacksonville African American Community who joined with the Mayo Clinic Florida Brain Health Team to participate in MarkVCID and ensure the community was represented in this important work. The MarkVCID program and its related studies are closed for new enrollment and actively following participants to evaluate change over time. Outcomes will become available upon the data collection and subsequent analyses.