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Estimation of Premorbid Intelligence in Schizophrenia

Published online by Cambridge University Press:  02 January 2018

J. R. Crawford*
Affiliation:
Department of Psychology, University of Aberdeen, Aberdeen AB9 2UB
J. A. O. Besson
Affiliation:
Department of Mental Health, Medical School, University of Aberdeen
M. Bremner
Affiliation:
Department of Mental Health, Medical School, University of Aberdeen
K. P. Ebmeier
Affiliation:
Department of Mental Health, Medical School, University of Aberdeen
R. H. B. Cochrane
Affiliation:
Department of Mental Health, Medical School, University of Aberdeen
K. Kirkwood
Affiliation:
Department of Mental Health, Medical School, University of Aberdeen
*
Correspondence

Abstract

To determine whether the National Adult Reading Test (NART) would provide a valid estimate of premorbid intelligence in schizophrenia, two schizophrenic samples were recruited, one consisting of 35 patients resident in long-stay wards, the other of 29 patients normally resident in the community. Schizophrenic patients were individually matched for age, sex, and education with a healthy, normal subject. Both schizophrenic samples scored significantly lower on the Wechsler Adult Intelligence Scale (WAIS) than their respective control groups. NART-estimated IQ did not differ significantly between the community-resident schizophrenics and their controls, suggesting that the NART provides a valid means of estimating premorbid intelligence in such a population. NART-estimated IQ was significantly lower in the long-stay sample than in their controls. Although low NART scores in this latter sample could be a valid reflection of low premorbid IQ, the alternative explanation that NART performance was impaired by onset of the disease cannot be ruled out.

Type
Papers
Copyright
Copyright © 1992 The Royal College of Psychiatrists 

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