OBJECTIVE: The purpose of the current study was to test the specificity
of an association between eye tracking abnormality and schizophrenia
spectrum personality symptoms in the family members of schizophrenic
patients. The studies of biological markers for genetic vulnerability to
schizophrenia, which test an association between a biological measure and
schizophrenia spectrum personality symptoms, are constrained, since these
personality symptoms may lack the specificity for a schizophrenic
phenotype. An association between a behavioral measure and these
personality symptoms in general can easily be false (i.e., not related to
schizophrenic vulnerability). In contrast, a strong deviant finding in the
relatives of schizophrenic patients with spectrum personality symptoms, in
the presence of a relatively normal finding in spectrum subjects without a
known history of schizophrenia, makes the biobehavioral measure an
interesting candidate for such investigations. METHOD: Seventy-five
subjects recruited from the community who did not have a family history of
psychosis completed the study (24 of the 75 had significant schizophrenia
spectrum personality symptoms). Thirty-two first-degree relatives of
schizophrenic patients (13 with spectrum symptoms) completed the study.
Subjects were 18-45 years old and had no DSM-III-R axis I diagnosis.
RESULTS: Qualitative smooth pursuit eye movement score was significantly
worse in relatives with the spectrum symptoms than in spectrum subjects
without a family history of schizophrenia and the nonspectrum relatives.
Schizotypal and schizoid symptoms explained a significant amount of the
variance in the eye tracking measure in the relatives (31% and 20%,
respectively) but not in the community subjects (less than 2%). Relatives
of schizophrenic patients with and without the spectrum symptoms had
significantly longer antisaccade latency, in spite of comparable latency
for visually guided saccades, than the community subjects. CONCLUSIONS:
Smooth pursuit abnormality in subjects with schizophrenia spectrum
personality disorders is specifically associated with a family history of
schizophrenia.Abstract Teaser