This study aims to compare the Theory of Mind (ToM) functions in the siblings and offspring of female Schizophrenia patients in an evaluation of the association between neurocognitive functions and ToM. A battery of ToM tests (Reading the Mind in the Eyes Test, Hinting Test and Faux Pas Test) and neurocognitive tests (Digit Span Test, Corsi Block Test, Digit Symbol Substitution Test, Rey's Auditory Verbal Learning Test, Trail Making Test, The Stroop Test, Wisconsin Card Sorting Test) were used to assess 31 offspring, 29 siblings of female schizophrenia patients and 28 healthy controls (HC). When the ToM functions of the offspring, siblings and HC groups in the present study are compared, no significant difference is identified between the offspring and sibling groups in Hinting, Faux Pas and Eyes tests, while Hinting test performance of the sibling group was significantly lower than those of the HCs. Neurocognitive functions are more affected both in offspring and siblings than HC. Although it was determined that ToM deficits of the patients' relatives were not as prominent as their neurocognitive functions, ToM is an endophenotype candidate in schizophrenia.
Keywords: Endophenotype; Schizophrenia; neurocognition; stait; theory of mind; trait.