J Korean Neuropsychiatr Assoc.  2009 Mar;48(2):86-91.

Theory of Mind Deficits in Schizophrenia Patients and Their First-Degree Relatives

• Lee JI
• Lee SH
• Kim SY
• Bae SM

Abstract

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.

Keyword

Theory of mind; Schizophrenia; Endophenotype; Schizotypal personality traits; First degree relatives

MeSH Terms

Endophenotypes
Humans
Surveys and Questionnaires
Schizophrenia
Theory of Mind