Multilingualism and psychosis: a pre-registered scoping review

Schizophrenia impacts several cognitive systems including language. Linguistic symptoms of schizophrenia are important to understand due to the crucial role that language plays in the diagnostic and treatment process. However, the literature is heavily based on monolingual-centric research. Multilinguals demonstrate differences from monolinguals in language cognition. When someone with schizophrenia is multilingual, how do these differences interact with their symptoms? To address this question, we conducted a pre-registered PRISMA-SR scoping review to determine themes in the literature and identify gaps for future research. Four hundred and twenty records were identified from three databases in 2023. Thirty articles were included in the synthesis. We found three emergent themes: (1) the need for multilingual treatment options, (2) differences in symptomology between the L1 and L2, and (3) the impact of cultural factors on linguistic functioning. Thus, several avenues of research regarding multilingualism may be fruitful for improving linguistic and social outcomes in schizophrenia.