Addressing language challenges in bilingual neuropsychological assessments at the South Texas Alzheimer's Disease Research Center (ADRC).

INTRODUCTION: Neuropsychological assessment of bilingual (English/Spanish) individuals presents challenges that can impact test validity. Language proficiency influences cognitive performance, yet clear guidelines for determining the appropriate test language are lacking. We describe our experiences at the South Texas Alzheimer's Disease Research Center (STAC) in addressing these challenges within the context of National Alzheimer's Coordinating Center (NACC) Uniform Data Set (UDS) assessments and broader Alzheimer's Disease Research Center (ADRC) protocols. We outline steps toward a structured language assessment approach. METHODS: We implemented a process to assess language proficiency, integrating self-reported and objective measures, including the language dominance index (LDI). Case examples illustrate the impact of language on cognitive testing. RESULTS: Challenges included discrepancies between self-reported and objective language proficiency, language switching during assessments, and resistance to testing in the dominant language. DISCUSSION: Language assessment improves test validity and research consistency. Future efforts should refine bilingual assessment methods and establish standardized protocols. HIGHLIGHTS: Systematic test language selection may improve accuracy in bilingual assessments. Discrepancies in reported versus objective language proficiency challenge bilingual assessments. Language evaluation guidelines are needed to improve test validity and data consistency.