A fresh look at the multi-level social determinants of disparities in Alzheimer's disease and related dementias.

The prevalence of Alzheimer's disease (AD) and related dementias (ADRD) worldwide is projected to triple to more than 150 million by 2050,1 posing a significant burden on individuals, families, and health-care systems. While measurable progress has recently been made in finding curative therapies for AD,2 the evidence supporting these therapeutics largely comes from studies that underincluded individuals from minoritized ethnoracial background.3 This is problematic especially in light of research that has revealed reliable racial differences in AD biomarkers, such as lower cerebrospinal fluid phosphorylated tau levels4 and reduced uptake of radioligands for amyloid5 among Black older adults compared to their White peers. The field is unquestionably at a watershed moment. A greater understanding is required of not only the biological processes that underlie the evolution of AD dementia, but also of the social-contextual factors that exacerbate or mitigate risk for AD. There is now ample evidence that the accumulated impact of structural and social determinants of health (SDoH) and associated sequelae persists over the life course, increasing the risk, disparities, and inequities associated with ADRD.6-8 This unacceptable status quo forms the motivation for this special issue, titled “Disparities and Multi-Level Social Determinants in ADRD” wherein 16 research groups from across the globe explore new and multidisciplinary approaches to understanding SDoH and their association with ADRD. In true reflection of the deeply multifaceted nature of this line of inquiry, the topics covered in this special issue span a diverse array of content areas such as SDoH-linked cognitive decline across racial groups, the lack of representativeness in ADRD research, the effects of early life experiences on late-life cognition, the impact of COVID-19 on cognitive impairment in older adults, the economic burden associated with mild cognitive impairment and mild dementia, proposals emanating from workshops and perspectives on improving access to timely diagnosis, differences in performance across racial groups on commonly used instruments for tracking cognitive change, and novel methodologies that can be used to better understand how the environment affects brain health.9-24 Taken together, the studies in this special issue bring us closer to identifying key constructs related to economic stability, social and community context, access to and quality of health care, and other things that are linked to cognitive outcomes and the progression to ADRD in minoritized older adults. Diversification of the ADRD scientific landscape and consideration of SDoH and intersectionality in ADRD research is now a public health imperative, as underscored by Milestone 1 of the National Institute on Aging AD/ADRD Research Implementation Milestones25 that calls for “a life-course approach across diverse populations to better understand how ancestry, race/ethnicity, sex, gender, and SDoH interact with exposome factors to influence risk of ADRD.” This special issue offers several novel intuitions for advancing this national mandate, and serves as a catalyst for further studies. We applaud the authors for their contributions and especially thank the reviewers for their partnership. The authors thank Drs Amy Kind and Sid O'Bryant, DADM Senior Associate Editors, for sponsoring this special issue and for their feedback on an earlier draft of this editorial. GBB is supported by Sistema Nacional de Investigación (SNI 063-2023) and SENACYT grant FID-22-092. OCO is supported by National Institutes of Health grants R01AG062167, R01AG077507, U19AG024904, U19AG078109, U19AG073153, R01AG066203, R01AG070028, R01AG027161, RF1AG052324, RF1AG059869, R01NS117568, and R01NS123378. The authors have no conflicts of interest to disclose. Consent was not necessary. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.