Do white matter hyperintensities account for the relationship between discrimination and memory?

INTRODUCTION: Racial discrimination (RD) relates to poorer memory, but underlying mechanisms are unclear. METHODS: Participants included 321 Black adults age 55+ from the Michigan Cognitive Aging Project. RD was operationalized with the Major Experiences of Lifetime Discrimination scale. Subjective memory was measured with the Memory Functioning Questionnaire. Episodic memory was a composite of list learning, story memory, and visual memory tests. White matter hyperintensities (WMHs) were quantified from T2 fluid-attenuated inversion recovery (FLAIR) images. Mediation models examined whether WMHs mediate the associations of racial discrimination on subjective and objective memory. RESULTS: More RD was associated with higher WMH volume. In turn, higher WMH volume was associated with worse objective, but not subjective, memory. Independent of WMH, more RD was associated with worse subjective, but not objective, memory. DISCUSSION: RD is an important intervention target to improve cognitive health equity and reduce WMH burden. RD may influence objective memory through vascular and/or inflammatory mechanisms.