Despite bilingualism being highly prevalent worldwide, the role of bilingualism in cognitive aging and Alzheimer's disease and related dementias (ADRD) remains inconclusive. Gaps include whether bilingual adults show reduced ADRD risk, how cognitive decline manifests across both languages, and what considerations are needed for accurate clinical assessment and intervention. The Bilingualism, Languages and Literacy Special Interest Group, part of the Diversity and Disparities Professional Interest Area, gathered an international, interdisciplinary group of researchers to identify key methodological factors impacting the study of bilingualism in cognitive aging and ADRD. Factors identified ranged from the operationalization and measurement of bilingualism, heterogeneity of bilingual populations, inconsistent accounting of sociocultural influences, scarcity of best practices in the clinical assessment and interventions of/for bilingual adults, and limited inclusion of conceptual frameworks. Findings generated reporting recommendations designed to increase rigor, comparability, and reproducibility across studies, and provide guidance for strengthening future research involving bilingual adults.
Keywords: ADRD; assessment; bilingual intervention; bilingualism; cognitive aging; cognitive reserve; culture; diversity; multilingualism.
© 2026 The Author(s). Alzheimer's & Dementia published by Wiley Periodicals LLC on behalf of Alzheimer's Association.