Clinical and etiological implications of a specific attention deficit in schizophrenia

Forty-seven psychiatric inpatients, including 26 schizophrenics and 21 nonschizophrenics, were measured on four clinical factors (chronicity, premorbid adjustment, reported symptomatology, and diagnosis) and four indices of reaction time (RT) performance (mean RT, RT variance, and redundancy-associated deficit [RAD] at 3- and 7-second preparatory intervals [PIs] ). Each clinical factor was analyzed in turn as a dependent variable in multiple regression analyses. The RT indices comprised the predictor set in each multiple regression. RAD at 7-second PI is related to chronicity for psychiatric patients in general and for schizophrenic patients in particular. Diagnosis and premorbid adjustment are related primarily to mean RT. No evidence was found that RAD is an artifact of high intertrial variance or long RT latencies, but intertrial variance does play a role in moderating the implications of RAD. The different correlations within schizophrenic and nonschizophrenic groups suggest a) that the Elgin Scale has a different meaning when used with schizophrenics than with nonschizophrenics, and b) that it is not useful to treat schizophrenic and nonschizophrenic disorders on the same continuum. The results in general suggest that the vulnerability factor thought to be associated with RAD militates for greater chronicity across different types of patients. The RAD effect within schizophrenics is nevertheless relatively greater than within other patients.