Objectives Blacks and Hispanics are at increased risk for dementia, even after socioeconomic and vascular factors are taken into account. This study tests a comprehensive model of psychosocial pathways leading to differences in longitudinal cognitive outcomes among older blacks and Hispanics, compared to non-Hispanic whites. Methods Using data from 10,173 participants aged 65 and older in the Health and Retirement Study, structural equation models tested associations among race/ethnicity, perceived discrimination, depressive symptoms, external locus of control, and 6-year memory trajectories, controlling for age, sex, educational attainment, income, wealth, and chronic diseases. Results Greater perceived discrimination among blacks was associated with lower initial memory level via depressive symptoms and external locus of control, and with faster memory decline directly. Greater depressive symptoms and external locus of control among Hispanics were each independently associated with lower initial memory, but there were no pathways from Hispanic ethnicity to memory decline. Discussion Depression and external locus of control partially mediate racial/ethnic differences in memory trajectories. Perceived discrimination is a major driver of these psychosocial pathways for blacks, but not Hispanics. These results can inform the development of policies and interventions to reduce cognitive morbidity among racially/ethnically diverse older adults.

Study Objective: Previous studies have identified shifts in gut microbiota associated with atypical antipsychotic (AAP) treatment, which may link AAPs to metabolic burden. Dietary prebiotics such as resistant starch may be beneficial in obesity and glucose regulation, but little is known mechanistically about its ability to modify gut microbiota in AAP-treated individuals. This investigation was undertaken to mechanistically delineate the effects of AAP treatment and resistant starch supplementation on gut microbiota in a psychiatric population. Design: Cross-sectional cohort study. Setting: The study was performed in an outpatient setting. Patients: Thirty-seven adults with a diagnosis of bipolar disorder or schizophrenia who were treated with an AAP (clozapine, olanzapine, risperidone, quetiapine, or ziprasidone [21 patients]) or lithium and/or lamotrigine (16 patients) for at least 6 months. Intervention: Patients in the AAP group received raw unmodified potato starch (resistant starch) daily for 14 days. Measurements and Main Results: Of the 37 patients, the mean ± SD age was 52.2 ± 12.5 years, and 57% were male. The primary outcome was gut microbiome DNA composition. Microbiome DNA obtained from stool samples from all patients was subject to 16S rRNA gene sequencing before and during resistant starch supplementation. Inter-and Intragroup microbial diversity measures were performed by permutational multivariate analysis of variance and Inverse

BACKGROUND/OBJECTIVES: Previous research suggests that everyday discrimination is associated with worse episodic memory and partially mediates Black-White disparities in memory aging. The biological mechanisms underlying the link between everyday discrimination and memory are unclear but may involve inflammatory processes. This study aimed to determine whether systemic inflammation, indexed by blood levels of C-Reactive Protein (CRP), mediates associations between everyday discrimination and episodic memory over six years. DESIGN: A longitudinal mediation model quantified associations between baseline everyday discrimination, four-year change in CRP, and six-year change in episodic memory. SETTING: The Health and Retirement Study (HRS). PARTICIPANTS: 12,624 HRS participants aged 51 and older. MEASUREMENTS: Everyday Discrimination Scale, high-sensitivity CRP assays of dried blood spots, composite scores of immediate and delayed recall of a word list. RESULTS: Black participants reported greater everyday discrimination. Greater discrimination was associated with lower baseline memory and faster memory decline. Higher CRP at baseline partially mediated the negative association between discrimination and baseline memory, but CRP change did not mediate the association between discrimination and memory decline. CONCLUSION: This U.S.-representative longitudinal study provides evidence for deleterious effects of discrimination on subsequent episodic memory. The fact that elevated CRP only partially explained the concurrent association between discrimination and memory highlights the need for more comprehensive investigations of biological mechanisms underlying the link between social stress and age-related memory decline in order to better characterize potential intervention targets to reduce racial inequalities in memory aging.

Objective: Previous research suggests that everyday discrimination is associated with worse concomitant performance in several cognitive domains, as well as faster subsequent declines in episodic memory. This study aimed to extend knowledge on the specificity, durability, and mechanisms of associations between everyday discrimination and cognition by using a comprehensive neuropsychological battery and a longitudinal mediation design. Method: Participants included 3,304 older adults in the Health and Retirement Study Harmonized Cognitive Assessment Protocol. Discrimination was assessed using the Everyday Discrimination Scale. Depressive symptoms were assessed with the 8-item Center for Epidemiological Studies Depression Scale. Vascular diseases were quantified as the self-reported presence of hypertension, diabetes, and heart disease. Confirmatory factor analysis was used to estimate episodic memory, executive functioning, processing speed, language, and visuoconstruction across a battery of 13 neuropsychological tests. Structural equation models controlled for sociodemographics and baseline cognition ascertained 2 to 4 years prior. Results: Discrimination was associated with more depressive symptoms and vascular diseases. Depressive symptoms mediated negative effects of discrimination on subsequent functioning across all 5 cognitive domains. Vascular diseases additionally mediated negative effects of discrimination on processing speed. After accounting for mediators, direct negative effects of discrimination remained for executive functioning and visuoconstruction. Conclusions: This national longitudinal study in the United States provides evidence for broad and enduring effects of everyday discrimination on cognitive aging, which appear to be partially mediated by mental and physical health. Future research should examine additional mechanisms as well as moderators of these associations to better understand points of intervention.