Smooth pursuit eye movements in schizophrenia and attentional dysfunction:Adults with schizophrenia, ADHD, and a normal comparison group

Background: Smooth pursuit eye movement (SPEM) abnormalities are found in s chizophrenia. These deficits often are explained in the context of the atte ntional and inhibitory deficits central to schizophrenia psychopathology. I t remains unclear, however, whether these attention-associated eye movement abnormalities are specific to schizophrenia or are a nonspecific expressio n of attentional deficits found in many psychiatric disorders. Adult attent ion-deficit/hyperactivity disorder (ADHD) is an alternative disorder with c hronic attentional and inhibitory dysfunction. Thus, a comparison of SPEM i n adult schizophrenia and adult ADHD will help assess the specificity quest ion. Methods: SPEM is recorded during a 16.7 degrees per second constant velocit y task in 17 adults with ADHD, 49 adults with schizophrenia, and 37 normal adults; all groups included individuals between ages 25-50 years. Results: Smooth pursuit gain and the frequency of anticipatory and leading saccades are worse in schizophrenic subjects, with normal and ADHD subjects showing no differences on these variables. Conclusions: Many attention-associated SPEM abnormalities are not present i n most subjects wit ADHD, supporting the specificity of these findings to t he attentional deficits seen in schizophrenia. Biol Psychiatry 2000;48:197- 203 (C) 2000 Society of Biological Psychiatry.