Neuropsychological differences between paranoid and nonparanoid schizophrenics on the Luria-Nebraska Battery

Neurodiagnostic findings have shown that some schizophrenics exhibit brain dysfunction. This study explored the relationship between neuropsychological performance and the paranoid/nonparanoid status dimension of schizophrenia. The Luria-Nebraska Neuropsychological Battery (LNNB) was administered to 45 paranoid schizophrenics, 45 nonparanoid schizophrenics, and 45 normal subjects. Group differences on the 14 major LNNB summary scales were evaluated. Differences favoring paranoids were found between the schizophrenic groups on five LNNB scales measuring complex motor functions, concentration, and the processing/retrieval of complex information. The pattern of results suggest paranoid/nonparanoid differences in functioning of the brain's frontal region, particularly in the left hemisphere.