Résumé
OBJECTIVES : Theory of mind (ToM) is the ability to conceptualize other people's mental states in order to explain their behavior. This study compared the ToM ability of schizophrenia patients, their first-degree biological relatives, and healthy controls. METHODS : ToM animation test was administered to schizophrenia patients (N=28), their healthy first-degree relatives (N=26), and healthy controls (N=28). The Korean version of schizotypal personality questionnaire (SPQ) was used to assess the schizotypal personality trait of all three groups. RESULTS : Schizophrenia patients and their first-degree relatives showed decreased accuracy on ToM animation test compared to healthy controls [F(2,78)=29.75, p<.001]. Additionally, first-degree relatives performed worse than the control group and better than schizophrenia patients. First-degree relatives had similar SPQ scores compared to healthy controls but showed decreased ToM accuracy compared to healthy controls. CONCLUSION : ToM deficits in schizophrenia patients are apparent. The ToM deficit in first-degree relatives of schizophrenia patients raises the possibility that ToM deficit may be a endophenotype for schizophrenia pathology.