Introduction

• Black and Latine Americans experience disproportionately

higher risk of Alzheimer’s disease (AD) compared to non-

Hispanic Whites (1).

• Racialized experiences, including discrimination and structural

inequities, are associated with higher rates of depression (2).

Depression has been linked to AD through several mechanisms,

including neurodegeneration and tau hyperphosphorylation (3).

• Present study examines whether racial identity modifies the

relationship between depression and two AD-relevant

biomarkers: phosphorylated Tau 181 (pTau181; marker of tau

hyperphosphorylation) and neurofilament light chain (NfL; marker

of neurodegeneration) in a diverse cohort.

 

Methods

• The sample included participants from the Health and Aging

Brain Study-Health Disparities (HABS-HD; N=2074; 62%

female).

• Depressive symptoms were assessed using the Geriatric

Depression Scale (GDS), with scores ranging from 0-30 and

higher scores indicating greater depressive symptom burden.

• pTau181 and NfL were selected from a larger plasma biomarker

panel to assess hyperphosphorylation and neurodegeneration.

• ANOVA examined group differences in GDS scores across

racial identities.

• Linear regression analyses assessed the association between

GDS scores and plasma biomarker concentrations (log-

transformed) and evaluated racial identity as a moderator using

a GDS x Racial Identity interaction term.

• Covariates: age, sex, APOE ε4 allele carriage, and

Body Mass Index (BMI).

 

Results Cont.

• Both Black and Hispanic participants had significantly

higher GDS scores than White participants (P< 0.001;

see Table 1.

• Higher GDS scores were associated with higher plasma

concentrations of both pTau181 (β = 0.02, P < 0.01) and

NfL (β = 0.02, P < 0.01) in Black relative to White

participants.

• The associations between GDS scores and both plasma

biomarkers (all Ps>0.12) were not significant for

Hispanic compared to White participants.

Discussion

• Minoritized racial groups experience higher levels of depression

compared to White individuals.

• Black individuals with greater depressive symptoms had higher

plasma concentrations of both tau hyperphosphorylation

(pTau181) and neurodegeneration (NfL) compared to White

individuals.

• Managing depressive symptoms may be a promising equity-

focused intervention for mitigating racial disparities in AD-related

risk. alteratio