SMOOTH-PURSUIT AND SACCADIC ABNORMALITIES IN FIRST-EPISODE SCHIZOPHRENIA

Background. Previous studies of oculomotor dysfunction in schizophreni a have tended to concentrate on abnormalities of smooth pursuit eye tr acking in chronic medicated patients. We report the results of a study of smooth pursuit, reflexive and antisaccade performance in drug naiv e and antipsychotic treated first-episode schizophrenic patients. Meth ods. Smooth pursuit and saccadic eye movements were recorded in 36 fir st-episode schizophrenic patients and 36 controls matched for age and estimated IQ. The schizophrenic patients were divided into drug-naive (N = 17) and antipsychotic treated groups (N = 19). Results. Smooth pu rsuit velocity gain was significantly lower than controls only in the drug-naive patients. The treated patients did not differ significantly from either the controls or the untreated group. In an antisaccade pa radigm both treated and drug-naive schizophrenic patients demonstrated an increased number of errors, but only drug-naive patients also demo nstrated an increased latency in initiating correct antisaccades. Conc lusions. These impairments are unlikely to be due to a generalized def icit in oculomotor function in the schizophrenic groups, as there were no differences between the groups in saccadic metrics on a reflexive saccade task. The results show that both smooth pursuit and saccadic a bnormalities are present at the onset of schizophrenia and are integra l to the disorder.