A NEUROPSYCHOLOGICAL STUDY OF EARLY-ONSET SCHIZOPHRENIA

Characterizing a pattern of cognitive dysfunction in early onset schiz ophrenic patients may illuminate neurodevelopmental contributions to t he illness. A cohort of chronically institutionalized schizophrenic pa tients with a variable range of age of onset (range 7-29 years) was ad ministered a comprehensive battery of neuropsychological tests that in cluded the Luria-Nebraska Neuropsychological Test Battery. After stati stical control of age, parental socioeconomic class (SES) effects, and thorazine equivalents, age of illness onset was positively correlated with performance on measures of motor ability, perceptual motor and p ure motor speed, receptive and expressive speech, and overall cognitio n function, and inversely related to severity of negative symptoms; th at is, earlier age of onset was associated with worse cognitive perfor mance and an increase in negative symptoms. This study demonstrates th at an early age of onset in schizophrenic illness is associated with i mpairment on tasks which involve motor and language abilities, functio ns linked to the frontal, temporal, and subcortical regions of the bra in. This association is not due to the effects of medication, negative symptoms, or duration of illness.