Perceived ethnic discrimination and cognitive function: A 12-year longitudinal study of Mexican-origin adults.

Objectives: Hispanic/Latinx adults are at increased risk for cognitive impairment, and it is critically important to identify modifiable risk factors for cognitive impairment in this population. We addressed two key questions: (1) How does perceived discrimination change across middle adulthood? And, (2) how are discrimination and the trajectory of discrimination associated with cognitive function?

Methods: We used data from 1,110 Mexican-origin adults between 26 and 62 years old (63% female; 85% born in Mexico). Participants completed a perceived ethnic discrimination scale five times across 12 years and completed cognitive assessments in the last wave, which were composited into a measure of overall cognitive function. We used latent growth curve models to estimate the longitudinal trajectory of perceived ethnic discrimination and growth mixture models to identify sub-groups of change trajectories. We evaluated whether patterns of perceived discrimination trajectories, baseline, intermediary, and concurrent discrimination predicted cognitive function at the last wave.

Results: Perceived ethnic discrimination decreased over time on average. Significant individual differences in within-person change revealed two change trajectory classes: Stable Low and High Declining. The Stable Low class had better cognitive performance compared to the High Declining class, but this effect was not robust to educational attainment. Perceived discrimination at the last wave was associated with worse cognitive function, and this effect remained after accounting for covariates.

Conclusions: This study is among the first to evaluate changes in perceived ethnic discrimination in a sample of Mexican-origin adults and their associations with cognitive function. The results highlight the need for more research to better understand the role of discrimination and other social stressors on cognitive health outcomes.