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

Abstract

The aim of this study was to investigate the possibility that 'theory of mind' (ToM) impairments are associated with schizophrenia liability. 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. 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. ToM deficits, as measured by the Eyes Test, are not associated with schizophrenia liability.