Depression is differentially related to cognitive and biomarker outcomes among Mexican Americans

Abstract

IntroductionDespite tremendous advancements in the research of Alzheimer’s disease (AD), Mexican Americans, who reflect 65% of the US Hispanic community, remain severely underrepresented in research. Our data demonstrate that risk factors for, and biomarkers of, AD are different among Mexican Americans as compared with non-Hispanic whites. Here, we examined the impact of depressive symptoms on cognitive and AD-relevant biomarker outcomes among the Mexican Americans.MethodsData were examined from 1,633 (852 Mexican Americans and 781 non-Hispanic whites) of the Health and Aging Brain Study–Health Disparities (HABS–HD). Depression was assessed using the Geriatric Depression Scale while cognition was measured using detailed neuropsychological testing. Plasma biomarkers of Aβ40, Aβ42, total tau, and NfL were examined in addition to MRI-based neurodegeneration. PET amyloid data were available in a subset of participants.ResultsDepressive symptoms were significantly associated with cognitive testing results among both Mexican Americans and non-Hispanic whites. However, depression was only significantly associated with cognitive outcomes and plasma biomarkers among the Mexican American APOEε4 non-carriers.DiscussionDepressive symptoms are more commonly endorsed by Mexican Americans and these symptoms are more strongly associated with cognitive and AD-biomarker outcomes among this ethnic group. However, depression scores were only related to AD outcomes among APOEε4 non-carriers within the Mexican American group. These findings can aid in the development of a population-informed precision medicine for treating and preventing cognitive loss among the Mexican Americans.

APOE Peripheral and Brain Impact: APOE4 Carriers Accelerate Their Alzheimer Continuum and Have a High Risk of Suicide in PM2.5 Polluted Cities

“…We need noninvasive biomarkers indicative of the P-tau and Aβ 42 abnormal protein deposits across the disease continuum starting in childhood. The need for non-invasive biomarkers is urgent and equally applicable to Mexican Americans, a highly vulnerable population, severely underrepresented in research [ 221 ]. There is no support for highly trained Mexican American researchers working on AD prevention.…”

Empirically derived psychosocial‐behavioral phenotypes in Black/African American and Hispanic/Latino older adults enrolled in HABS‐HD: Associations with AD biomarkers and cognitive outcomes

“…In contrast, there were no differences in performance on the memory composite across the phenotypes. The larger literature has highlighted that executive dysfunction is commonly observed within these ethnoracial groups, and elevated rates of vascular risk and psychiatric symptoms may represent mechanisms underlying this observation 62–66 . With regard to memory, the relationship between subjective concerns and objective performance is small, 67,68 and investigators have noted differences in the frequency and severity of subjective cognitive concerns between ethnoracial groups 69,70 .…”

“…The larger literature has highlighted that executive dysfunction is commonly observed within these ethnoracial groups, and elevated rates of vascular risk and psychiatric symptoms may represent mechanisms underlying this observation. 62 , 63 , 64 , 65 , 66 With regard to memory, the relationship between subjective concerns and objective performance is small, 67 , 68 and investigators have noted differences in the frequency and severity of subjective cognitive concerns between ethnoracial groups. 69 , 70 Since subjective memory concerns have been tightly linked with affective symptoms, 7 we suspect the notable differences in subjective, but not objective, memory performance may have been a function of psychiatric distress within the Low Resource/High Distress phenotype.…”