Risk of Alzheimer's disease and related dementias (ADRD) is higher for non-Latinx Black older adults than for
non-Latinx White older adults. This disparity is not fully explained by commonly measured individual risk
factors such as educational disadvantage, apolipoprotein E epsilon 4, or medical comorbidities. Thus, there is
a critical need to identify additional modifiable targets at multiple levels to reduce ADRD inequalities in line with
NIA's Strategic Directions for Research and the NIA Health Disparities Framework. The overall goal of this
longitudinal study (N=700; 50% Black) is to identify new, modifiable pathways to reduce racial inequalities in
ADRD by leveraging the community-based Michigan Cognitive Aging Project (MCAP), the National
Neighborhood Data Archive (NaNDA), and recently released historical data from the 1950 census. Our strong
preliminary data support concurrent neighborhood socioeconomic status (nSES) as a unique driver of cognitive
inequalities that operates through modifiable environmental (e.g., public infrastructure), social (e.g.,
discrimination), psychological (e.g., depressive symptoms), and behavioral (e.g., diet) mechanisms. The
current proposal will follow MCAP participants for a critical third time point to enable latent growth curve
modeling of longitudinal cognitive trajectories, expand the cohort to ensure adequate power for between and
within group longitudinal analyses in the presence of racial disparities in mortality, and collect structural
magnetic resonance imaging (MRI) measures of brain integrity. In addition, this proposal will collect new data
on residential histories to identify life course critical periods for neighborhood level interventions, develop a
novel measure of neighborhood racial income inequality that could predict ADRD risk above and beyond
nSES, and reveal resilience factors among Black older adults that could interrupt ADRD risk pathways. Recent
studies have linked nSES to brain and cognitive outcomes, but the mechanisms, modifiers, and intersection
with racial inequalities in ADRD are not yet understood. Grounded in the bioecological model and a life course
model of ADRD inequalities, our overarching hypothesis is that eliminating racial inequalities in ADRD will
require interventions at multiple levels of the exposome, and the current proposal will provide actionable
knowledge to guide policies and interventions.