A comparative study of theory of mind in taxon-like clusters of psychometric schizotypes and individuals at genetic risk for schizophrenia.

Abstract

Introduction: Clinical and family studies suggest that alterations of theory of mind (ToM) represent a marker of genetic liability to schizophrenia. Findings regarding ToM in schizotypy are less consistent. The study aimed to explore whether this might be due to an insufficient account of the heterogeneity of schizotypy in prior research and/or the fact that in psychometric schizotypy ToM alterations could manifest as subtle peculiarities rather than overt errors of mentalising.Methods: Individuals without a family history of psychosis (n = 150) were assigned to low, positive, negative, and high mixed schizotypy classes based on a cluster analysis of 1322 subjects who completed the Schizotypal Personality Questionnaire. The classes were compared on their performance of faux pas tasks with 77 adult first-degree relatives of schizophrenia patients, who represent individuals at genetic risk for schizophrenia. Besides overt errors, subtle alterations in ToM were analysed using expert judgment.Results: The relatives tended to make overt errors and demonstrated specific features of intentional reasoning. None of the schizotypal classes showed similar trends.Conclusions: The results complement the literature on the subjective-objective disjunction in psychometric schizotypes and did not provide evidence that ToM anomalies are a marker of genetic liability to schizophrenia in this cohort.