Cognitive differences between healthy monolingual and bilingual anglophones on the English version of the Depistage Cognitif de Quebec: A new screening tool for atypical dementia

Aims and Objectives: Cognitive abilities between monolingual and bilingual individuals may differ, making it an important factor to consider during the administration of cognitive screening tools. Otherwise, assessments could be subject to misinterpretation, leading to possible inaccurate diagnoses. The current project aimed to compare cognitive performance of healthy older monolingual and bilingual anglophones on the English version of a new cognitive screening test designed for better recognition of atypical dementia: the Depistage Cognitif de Quebec (DCQ; www.dcqtest.org). Design: The DCQ was administered by qualified psychometricians to 85 native English-speaking participants aged 50 years and over, in various sites across Canada. Language proficiency was established using the Language Experience and Proficiency Questionnaire (LEAP-Q). The Montreal Cognitive Assessment (MoCA) was used to exclude individuals with cognitive impairments. Data and Analysis: Amid the anglophone participants recruited, 30 monolingual anglophones and 29 bilingual anglophones (English and French) met inclusion criteria. Groups had similar age, education, and MoCA scores. Monolinguals and bilinguals were compared on their total DCQ scores and each of the five DCQ indexes: Memory, Visuospatial, Executive, Language, and Behavioural. Findings: The bilingual participants performed better on the Language Index, which contributed to the significant bilingual advantage for the overall DCQ scores. When applying a Bonferroni correction, the differences between groups were, however, not maintained. No differences were found on any of the other indexes. Originality: This study is the first to explore psychometric properties of the DCQ in older monolingual and bilingual participants tested in their native language.