Population Studies: Diverse cohorts

Continue to establish new cohorts that include participants across diverse racial, ethnic and socioeconomic backgrounds and incorporate the collection of multi-omic and clinical data (imaging, personal wearables, and sensors for in-home monitoring) to accelerate the identification of genomic variants and other risk and protective factors contributing to the heterogeneity and multifactorial etiology of dementia and to enable the development of predictive models of disease and wellness. Ensure that these cohorts represent the current and future projected population priorities.

Establish at least 3 new cohorts that incorporate deep molecular endophenotyping with participants of African, Native American, Asian, and mixed ancestry, e.g. Latinos, as well as younger cohorts (midlife and younger participants). The phenotyping should include cognitive, behavioral, imaging, exposome measurements, multidimensional “omics” data (generated from the target tissue as well as peripheral tissues) and multiple types of physiologic measurements that can be used for systems biology and gene-environment interaction studies.
Improve research rigor in cohort studies by incorporating assessment of the impact of social determinants of health (SDOH) and by supporting uniform genotyping/deep sequencing, by standardizing biosamples collection (brain, CSF, blood and stool specimens) as well as blood and CSF biomarker assays.
These programs should include big data infrastructure resources to ensure that the data are made available as a public resource and support for collection, storage and rapid distribution of biosamples (e.g., brain tissue, CSF, blood and stool specimens).

Summary of Key Accomplishments

NIA supports several life-course studies of diverse populations that collect and share a depth and breadth of data. The HABS-HD study (Health and Aging Brain Study – Health Disparities) is a cohort study with multi-ethnic participants (1,000 Mexican Americans, 1,000 African Americans, 1,000 non-Hispanic Whites) and has a major focus on participant engagement biobanking and rapid sharing of data.

Another example is the Multi-phasic Health Study, a large life-course study of the oldest-old (90 years+), including those from populations historically underrepresented in dementia research, to identify risk and protective factors for AD/ADRD; for each participant, rich health data, including disease biomarker data, are being collected over a 30-50-year period.

The follow up study for the Multi-phasic Health Study was the Kaiser Healthy Aging and Diverse Life Experiences (KHANDLE) Study. KHANDLE is one of the largest life-course cohorts with diverse racial/ethnic composition and prospective clinical, lifestyle, and behavioral data from 1964 to present. The Project Talent Aging Study is a national longitudinal study that began surveying America’s high school students in 1960. Leveraging data from Project Talent, researchers have been able to examine whether attending higher quality schools is associated with cognitive performance among older adults in the United States, as well as if early-life cognitive skills among Black and White participants account for educational differences in late-life cognition. Other work with Project TALENT taking advantage of the Centers for Medicare and Medicaid Services’ billing data linkages has demonstrated, for example, the association of personality characteristics in adolescence and dementia risk over 50 years later.

NIA also supports the Asian Cohort for Alzheimer’s Disease (ACAD) project, which will build the first major AD genetics study for Asians in the United States and Canada. The project will lead to new genetic and lifestyle screening markers for Asian Americans and insights about novel therapeutic targets for AD. The Precision-CARRS-BRAIN project leverages the ongoing Precision-CARRS cohort, a diverse population of more than 20,000 South Asian adults starting in midlife, to investigate factors associated with early and late AD/ADRD stages. The goal is to advance progress in understanding the natural history of AD/ADRD along the life course and promote early detection, precise diagnosis and tailored therapeutic strategies for this high-risk, understudied population and beyond.

NIA supports the Harmonized Cognitive Assessment Protocol (HCAP), which was originally designed to allow researchers to “cross-walk” between the cognitive tests given to participants in the Health and Retirement Study (HRS) and other large U.S. cohorts including the ROS/MAP project and ADNI. Subsequently, the translation and adaptation of the HCAP protocol in the U.S. to several other countries in the Health and Retirement Study (HRS) partner studies around the world, has enabled understanding of how dementia risk differs between countries and which risk factors from the U.S. context are shared or not shared elsewhere in the world. To date, HCAP studies have been completed, and data is available in 12 countries including Chile, China, Czech Republic, Denmark, England, France, Germany, India, Italy, Mexico, South Africa, and the U.S. HCAP studies are underway but not yet completed in 11 additional countries including Cameroon, Cote D’Ivoire, Costa Rica, Dominican Republic, Egypt, Ireland, Kenya, Lebanon, Nepal, Northern Ireland, and Pakistan. Between September 2024 and August 2025, updates included new diagnosis variables and survey weights to the 2016 U.S. HRS-HCAP and new data releases from Longitudinal Aging Study in India – Diagnostic Assessment of Dementia (LASI-DAD); Survey of Health, Aging, and Retirement in Europe (SHARE -Czech Republic, Denmark, France, Germany, Italy); The Irish Longitudinal Study on Ageing (TILDA -Republic of Ireland); the Northern Ireland Cohort for the Longitudinal Study of Ageing (NICOLA); and Chile-Cog.

In addition, NIA funding supports the generation of genomic data from multi-ethnic cohorts for the Alzheimer’s Disease Sequencing Project Follow-Up Study (ADSP FUS) 2.0, which includes individuals from Hispanic/Latino, Black/African American, and Asian populations to identify population specific as well as rare and very rare variants in AD/ADRD. While still ongoing, the ADSP FUS 2.0 has already identified both unique risk and protective variants that vary by diversity group. Structural variants also vary across populations. Data resulting from this study are available to the research community through the NIA Genetics of Alzheimer’s Disease Data Storage Site (NIAGADS).

In addition, NIA has announced 21 related funding initiatives, including one that recently funded five projects to establish infrastructure for precision medicine research in AD/ADRD, focusing on health disparities. The five awards will initiate innovative, integrated, and expanded research including individuals from populations understudied in AD/ADRD.

The key accomplishments summary is current as of September 2025.