Smooth pursuit and saccadic abnormalities in first-episode schizophrenia.

Background. Previous studies of oculomotor dysfunction in schizophrenia have tended to concentrate on abnormalities of smooth pursuit eye tracking in chronic medicated patients. We report the results of a study of smooth pursuit, re¯exive and antisaccade performance in drug naive and antipsychotic treated ®rst-episode schizophrenic patients. Methods. Smooth pursuit and saccadic eye movements were recorded in 36 ®rst-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 pursuit velocity gain was signi®cantly lower than controls only in the drug-naive patients. The treated patients did not differ signi®cantly from either the controls or the untreated group. In an antisaccade paradigm both treated and drug-naive schizophrenic patients demonstrated an increased number of errors, but only drug-naive patients also demonstrated an increased latency in initiating correct antisaccades. Conclusions. These impairments are unlikely to be due to a generalized de®cit in oculomotor function in the schizophrenic groups, as there were no differences between the groups in saccadic metrics on a re¯exive saccade task. The results show that both smooth pursuit and saccadic abnormalities are present at the onset of schizophrenia and are integral to the disorder