Preliminary study of higher-order language and extralinguistic impairments in individuals with high clinical risk of psychosis and first episode of schizophrenia

Abstract

Aim: Higher-order language functions are associated with understanding indirect speech acts, lexical-semantic processes, the understanding and production of prosody, discourse production and comprehension. Only a few studies imply that language abnormalities may be present in individuals at ultra-high risk for psychosis (UHR) and first-episode of schizophrenia (FE). The purpose of this study was to test the presence of higher-order language dysfunctions in UHR and FE subjects using a standardized comprehensive test battery.

Methods: Twenty patients experiencing FE schizophrenia, 33 UHR individuals and 20 healthy controls (HC) took part in the study. Higher-order language and extralinguistic abilities were evaluated using the Right Hemisphere Language Battery (RHLB-PL). The battery consisted of tests covering the comprehension of implicit information, lexico-semantic processing, understanding humour, making inappropriate remarks and comments, understanding and explaining metaphors, understanding prosody and appropriateness of behaviour in communication settings.

Results: The UHR patients scored lower than HC when comprehending implicit information, discourse and in areas associated with the effectiveness of interpersonal communication; however, they scored higher than the FE participants in explanation of metaphors and processing language information in the context of general knowledge. The FE participants scored lower than healthy controls in comprehension of implicit information, explanation of metaphors, discourse understanding, processing language information in the context of general knowledge and effectiveness of interpersonal communication.

Conclusions: The higher-order language dysfunctions mediated by the right hemisphere appear to be present in subjects at UHR of schizophrenia and those experiencing their FE. The results may play a crucial role in diagnostic processes.

Keywords: communication; extralinguistic processes; first episode schizophrenia; language; ultra high risk for psychosis.