Diglossia Correlates With Prodromal Symptoms of Psychosis Among First-Generation Migrants.

Background and Hypothesis: We have previously hypothesized that diglossia may be a risk factor for psychosis, drawing from observations on migration, ethnicity, social adversity, and language disturbances among others. However, empirical data on this association and the tools necessary for its measurement are limited. Study Design: In a cross-sectional online sample of first-generation migrants residing in majority English-speaking countries, a response-based decision tree was introduced to classify the sociolinguistic profiles of 1497 participants as either with or without diglossia. Using multivariate logistic regression, the association of diglossia with psychosis risk screening outcomes in the Prodromal Questionnaire-16 was calculated, adjusting for demographic and linguistic confounders. Differences in the symptom categories endorsed between the 2 groups were also examined. Study Results: Diglossia was identified in 18.4% of participants and was associated with an adjusted odds ratio of 2.58 for a positive risk screening outcome. Other significant factors included subjective social status, hearing difficulty, age, sex, country of residence, education level, and cannabis consumption. The effects of ethnicity, age at migration, fluency, relationship, and employment status were no more significant in the multivariate model. Finally, the largest differences in the proportion of positively responding participants between the two groups were found in symptoms relating to thought insertion and thought broadcasting. Conclusions: In a sociolinguistic hierarchical framework, diglossia is correlated with prodromal symptoms of psychosis in first-generation migrants.