Add Health Parent Study: A Biosocial Resource for the Study of Multigenerational Racial/Ethnic Disparities in Alzheimer's Disease and Alzheimer's Disease-Related Dementias (AD/ADRD)

Abstract Significant knowledge gaps exist regarding intergenerational dimensions of cognitive aging and risk for Alz- heimer’s Disease and Alzheimer’s Disease Related Dementias (AD/ADRD), and how these processes differ across race and ethnic groups. The proposed Add Health Parent Study (AHPS) Phase 2 is designed to ad-

dress these gaps. AHPS is an ongoing study of social, behavioral, and biological factors influencing healthy aging and the development of AD/ADRD in a national sample of adults currently aged 58-90. Sample members are parents of the National Longitudinal Study of Adolescent to Adult Health (Add Health) cohort, initially inter-

viewed in Add Health in early midlife (1994-95) before differential survival could contribute bias to sample rep- resentation. Phase 1 of AHPS (2015-17) collected longitudinal data on a random subsample of parents and their spouse/partners (S/P, N= 3001), the majority (73%) of whom were Non-Hispanic (NH) White. Phase 2 of

AHPS will collect social, behavioral, and health data on all available NH Black and Hispanic parents (BHS sup- plement, N= 2,505), and cognitive assessments and DNA data on all AHPS Phase 1 and BHS sample parents and their current S/P (total N= 5,506). By adding NH Black and Hispanic parents, AHPS will be sufficiently sta-

tistically powered to address, for the first time, measurement of health, social, and behavioral differences in AD/ADRD risk and protective factors across race/ethnic groups and socioeconomic strata. Combined data from AHPS Phases 1 and 2 will be linked with rich longitudinal data on original Add Health re-

spondents to create and disseminate the first nationally representative multigenerational biosocial resource with cognitive, genomic, behavioral, and social data for the study of racial/ethnic disparities in cognitive aging and AD/ADRD risk. Cognition and genomic data will be harmonized across the two generations of parents and

children for innovative analysis of intergenerational predictors of AD/ADRD; the role of genetic processes in AD/ADRD etiology; and intergenerational and lateral caregiving. Project specific aims are: 1a. Recruit and interview additional sample of 2,505 NH Black and Hispanic parents with the AHPS survey.

1b. Consent all 5,506 AHPS members for participation in AD/ADRD Assessment and DNA data collection. 2a. Collect DNA and conduct SNP genotyping and DNA methylation analysis on AHPS sample. 2b. Develop an intergenerational genomic database to advance an understanding of the gene-environment interplay in the etiology of AD/ADRD.

3a. Examine novel longitudinal and intergenerational social, health, and behavioral risk and preventive factors for AD/ADRD across racial/ethnic groups and social strata. 3b. Examine AHPS members’ caregiving experiences and the socioeconomic consequences of caregiving ex- periences related to AD/ADRD conditions or risks.

4. Document, disseminate, and promote use of AHPS data to the global scientific community.