Relatives of unipolar and bipolar patients have normal pursuit.

Impaired smooth pursuit eye movements are significantly less prevalent among the first-degree relatives of patients who have major affective disorders than among the first-degree relatives of schizophrenics. The distribution of normal and abnormal smooth pursuit among the relatives of unipolar and bipolar patients does not differ from that of normal individuals having no family history of major psychosis. Smooth pursuit impairment is thus specific to relatives of schizophrenic patients and is not characteristic of relatives of patients with major affective disorders.