Increasing evidence suggests that smooth pursuit eye movement (SPEM)
dysfunction may serve as an endophenotype or genetic marker of
schizophrenia. The authors tested SPEM and visual fixation (VF) in 31
patients with schizophrenia, 33 of their first-degree relatives, and 24
patients with major depressive disorder. A high rate of abnormal VF was
found in schizophrenic patients and their first-degree relatives, but not
in affective disorder patients with or without psychotic features. Rate of
VF abnormality distinguished schizophrenic patients from acutely depressed
mood disorder patients; SPEM did not. VF and SPEM performance correlated
only moderately, suggesting that the pathophysiologies of these two eye
movement abnormalities may be partially independent. Implications for
identifying a schizophrenia endophenotype are discussed.Abstract Teaser