We have previously demonstrated that Spanish-speaking schizophrenic patients interviewed in English are judged by experienced raters as significantly more psychopathological than when interviewed in their native tongue. In this study behavior in the two interview situations was compared directly.
Compared to the parallel Spanish-language situation, patients interviewed in English demonstrated more content indicative of psychopathology, more frequent misunderstandings of the interviewer, briefer responses, and a significantly higher frequency of speech disturbances previously shown to be associated with anxiety. They tended to speak more slowly and with longer silent periods, characteristics associated with depression. Unless he is aware of these features, the clinician may interpret them as reflecting increased psychopathology.
Marcos LR, Urcuyo L, Kesselman M, Alpert M. The Language Barrier in Evaluating Spanish-American Patients. Arch Gen Psychiatry. 1973;29(5):655-659. doi:10.1001/archpsyc.1973.04200050064011