No evidence for impaired 'theory of mind' in unaffected first-degree relatives of schizophrenia patients

Objective: The aim of this study was to investigate the possibility that 'theory of mind' (ToM) impairments are associated with schizophrenia liability. Method: Forty healthy control subjects and 79 first-degree biological relatives of schizophrenia patients (32 siblings and 47 parents) received the Eyes Test, during which subjects are asked to choose the word best describes the mental state of a person whose eyes are depicted on a photograph. Results: The affected relatives (n = 14) performed worse on the Eyes Test compared with the controls (P = 0.0001), whereas the unaffected relatives (n = 65) showed intact performances (P = 0.4). The Eyes Test values did not correlate with age and IQ. There was no significant difference between male and female participants. Conclusion: ToM deficits, as measured by the Eyes Test, are not associated with schizophrenia liability.