Neuropsychological differentiation of chronic schizophrenia.

Four groups of 20 each (chronic brain-damaged schizophrenics, chronic non-brain-damaged schizophrenics, chronic non-brain-damaged with "acute" exacerbation, and control subjects) were individually administered Form I of the Luria Nebraska Neuropsychological Battery (LNNB). Control subjects scored significantly lower than all clinical groups on all scales except for the chronic non-brain-damaged schizophrenics on the Reading Scale. "Acute" schizophrenics scored higher on Motor, Visual, Receptive Speech, Intellectual Processes, Pathognomonic, Right Hemisphere and Profile Elevations scales than the other clinical groups. Chronic brain-damaged schizophrenics scored significantly higher than chronic non-brain-damaged schizophrenics on the Profile Elevation scale. To examine the possibility that LNNB performance of the schizophrenic groups may have been related to neuroleptic medication, analyses were completed on the relationship between medication levels and LNNB scores. These results suggested that while the three clinical groups differed in their chlorpromazine equivalents (CPZE), LNNB scores were not related to CPZE dosage.