Dyslexia in Bilinguals: a PRISMA Systematic Review

Research on dyslexia and bilingualism has largely been conducted separately (Cline, 2000). This systematic review explores the interaction between bilingualism and dyslexia by summarising and synthesising studies that include bilingual dyslexic readers (DRs). The goal is to identify aspects of dyslexia that are independent of multilingual experience and to determine the most appropriate diagnostic tests for bilingual populations. We include 40 studies, categorised into three groups: studies involving only bilingual dyslexic and typical readers (TRs), studies comparing monolingual and bilingual DRs and TRs, and studies predicting poor reading in bilingual populations. Our findings indicate that rapid naming and reading impairments remain prevalent in bilingual dyslexic populations. Phonological awareness, a common deficit in dyslexia, appears to be less impaired in bilingual readers. Notably, language experience is associated with more differences in DRs than TRs, suggesting that bilingualism may interact with relevant skills more markedly in dyslexic than in typically reading individuals. In predictive studies, the high variability across studies does not allow for evidence-based recommendations for reliable diagnostic measures. Future research should focus on clearly defining the language profiles of participants and should ensure that assessments account for linguistic experience in the language of testing. Additionally, evaluations should adopt a more comprehensive and individualised approach to accurately assess bilingual readers.