Psychological Science Faculty Publications and Presentations

Document Type

Article

Publication Date

7-7-2025

Abstract

Introduction: Apolipoprotein allele 4 (APOE ε4) is associated with lower IQ scores during childhood and adolescence, but the influence of APOE ε4 and low IQ on late-life cognition is unknown. This study examines the association between APOE ε4 and cognitive outcomes based on premorbid intellectual ability (pIQ) and ethnic background.

Methods: Participants were drawn from the Health & Aging Brain Study–Health Disparities (HABS-HD), categorized by low (z ≤ −2.00) or average (z = 0.00 ± 1.00) pIQ based on word reading scores. Statistical analyses were conducted to evaluate whether APOE ε4 was associated with the cognitive domains of episodic memory, executive functioning, processing speed, and language by pIQ and ethnicity.

Results: APOE ε4 was associated with worse cognitive performance across domains. In the overall sample analysis, the deleterious effect of ε4 on processing speed and executive functioning was stronger among those with low pIQ. In stratified analysis, the negative impact of APOE ε4 was stronger among non-Hispanic White individuals with low pIQ for episodic memory and Hispanic individuals with low pIQ for processing speed.

Discussion: The influence of APOE genotype on cognitive outcomes is moderated by ethnicity and premorbid IQ, positioning low pIQ, a proxy for intellectual disability (ID), as a population more vulnerable to the negative effects of APOE ε4 in older adulthood.

Conclusion: The effect of Alzheimer’s disease (AD) risk genes on cognitive performance may not mirror what is observed in AD-Down syndrome, highlighting the urgent need to expand AD research to reach more representative populations with I/DD.

Comments

Doctoral student.

© 2025 Abdullah, Zhou, Alliey, Barber, Hall and O’Bryant. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

Creative Commons License

Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.

Publication Title

Frontiers in Neurology

DOI

10.3389/fneur.2025.1627525

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