Saccadic distractibility is elevated in schizophrenia patients, but not in their unaffected relatives.
BACKGROUND
Saccadic distractibility, as measured by the antisaccade task, has attracted attention as a putative endophenotypic marker for schizophrenia. Some studies have suggested that this measure is elevated in the unaffected relatives of schizophrenia patients. However, recent studies have called this into question and the topic remains controversial.


METHODS
Saccadic distractibility was measured in 53 patients with DSM-IV schizophrenia, 80 unaffected first-degree relatives and 41 unaffected controls.Results. Schizophrenia patients performed worse than relatives and controls combined (p<0.00001), but relatives did not differ significantly from controls. Performance in multiply affected families was no worse than that in singly affected families. Relatives with a high presumed genetic risk for schizophrenia performed no worse than other relatives. The performance of the patients did not predict that of their relatives.


CONCLUSIONS
These results demonstrate that saccadic distractibility is strongly associated with disease status but not with genetic loading for schizophrenia. We conclude that saccadic distractibility is unlikely to be useful as an endophenotypic marker in schizophrenia.
Maccabe
James H
JH
Division of Psychological Medicine, Institute of Psychiatry, London, UK.
Simon
Helen
H
Zanelli
Jolanta W
JW
Walwyn
Rebecca
R
McDonald
Colm D
CD
Murray
Robin M
RM
D000328:Adult; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005190:Family; D005260:Female; D006801:Humans; D008297:Male; D010641:Phenotype; D012438:Saccades / Q000502:physiology*; D012559:Schizophrenia / Q000175:diagnosis / Q000235:genetics* / Q000503:physiopathology*; D012720:Severity of Illness Index