Theory of mind performance in schizophrenia: diagnostic, symptom, and neuropsychological correlates.

The purpose of this study was to explore the relationship between Theory of Mind (ToM) performance and schizophrenia subtype, symptom, and neuropsychological variables. One hundred twenty-eight stable outpatients with schizophrenia or schizoaffective disorder were assessed during the intake phase of a vocational and cognitive rehabilitation study. Results indicate that ToM performance differed significantly by schizophrenia diagnosis, with people diagnosed with disorganized schizophrenia performing the most poorly. Theory of Mind performance was also significantly correlated with measures of thought disorder and verbal memory. Regression analysis revealed that thought disorder and verbal memory measures explained 30% of the variance in ToM scores. Findings suggest that there is theory of mind variance in the schizophrenia population and theory of mind is strongly related to thought disorder, verbal memory, and cognitive disorganization. Contrary to previous reports, ToM was not related to measures of paranoia.