Alterations in theory of mind in patients with schizophrenia and non-psychotic relatives.
OBJECTIVE
It has been proposed that alterations in theory of mind underlie specific symptoms of psychosis. The present study examined whether alterations in theory of mind reflect a trait that can be detected in non-psychotic relatives of patients with schizophrenia.


METHODS
Participants were 43 patients with schizophrenia or schizoaffective disorder, 41 first-degree non-psychotic relatives and 43 controls from the general population. Theory of mind was assessed using a hinting task and a false-belief task.


RESULTS
There was a significant association between schizophrenia risk and failure on the hinting task (OR linear trend = 2.01, 95% CI: 1.22-3.31), with relatives having intermediate values between patients and controls. Adjustment for IQ and neuropsychological factors reduced the association by small amounts. The association between schizophrenia risk and failure on the false-belief tasks was not significant.


CONCLUSIONS
Changes in theory of mind are associated with schizophrenia liability. General cognitive ability and neuropsychological measures seem to mediate only part of this association.
Janssen
I
I
Department of Psychiatry and Neuropsychology, azM/Mondriaan/Riagg/RIBW/Vijverdal Academic Centre, EURON, Maastricht University, Maastricht, The Netherlands.
Krabbendam
L
L
Jolles
J
J
van Os
Jim
J
D000328:Adult; D016022:Case-Control Studies; D003071:Cognition; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008960:Models, Psychological; D011603:Psychophysiology; D012307:Risk Factors; D012559:Schizophrenia / Q000235:genetics* / Q000503:physiopathology*; D012565:Schizophrenic Psychology