Adult Changes in Thought (ACT) Research Program

The Adult Changes in Thought (ACT) U19 Program will expand, modernize, and improve ACT's prospective cohort study to achieve advances in scientific understanding of older adults in general and dementia and Alzheimer's disease in particular. ACT is set in a healthcare delivery system. The study team identifies incident

cases of dementia and Alzheimer's disease and follows consenting participants to autopsy. The Program will transform the current ACT U01 to a U19, which envisions complex multi-component programs that will have a powerful influence on the field. The Program's overarching goal is to identify risk factors across the life course

that provide potential intervention targets for preserving cognition and preventing Alzheimer's disease and related dementias (ADRD). The Overall Specific Aims are: Aim 1. Expand ACT cohort enrollment and modernize and improve follow-up with emphasis on increasing racial/ethnic diversity and deep phenotyping of

life course risk factors, cognitive and physical functioning, and outcomes including neuroimaging and neuropathology based ADRD outcomes. The Cores will expand cohort enrollment from 2,000 to 3,000. The study will invest in six Cores: A, Administrative; B, Clinical; C, Life Course; D, Neuropathology; E,

Neuroimaging; F, Data and Analysis. These Cores will work together to further enhance the value of ACT's resources, enabling the ACT study to continue to be the foundation for an extraordinary array of science. To date, ACT has achieved a completeness of follow-up index of 94.5% and has observed 56,140 person-years of

follow-up. ACT has identified >1,300 incident dementia cases and >1,000 incident Alzheimer's cases. The study has completed >850 autopsies and will surpass 1,100 autopsies this cycle. Additionally, 1,077 ACT participants had one MRI scan, and 540 have had ≥2, with funding in place for hundreds more. Aim 2. Support

key Projects studying the spectrum of healthy functioning to ADRD in older adults. The three Projects center around 24-hour cycle physical activity, sedentary behavior, and sleep patterns in old age (Project 1), the implications of cognitively defined Alzheimer's disease subgroups (Project 2), and mechanisms underlying

neural protection and toxicity of strong anticholinergic drugs and antihypertensive drugs (Project 3). Aim 3. Expand and improve ACT's dissemination of exceptional resources to the research community guided by NIA's adopted FAIR (Findable, Accessible, Interoperable, and Reproducible) principles. ACT has proven to be an

exceptional resource to the research community, providing data and specimens to research colleagues locally, across the country, and around the world, and provides mentorship to junior investigators. We will continue to enhance our data sharing capabilities in this U19 Program.