A cluster analytic solution based upon a battery
of tests consisting of the Halstead Category and Tactual
Performance Tests, the Trail Making Test, and the Wisconsin
Card Sorting Test was compared with a solution based on
the subtests of the Wechsler intelligence scales, utilizing
a sample of 221 schizophrenic patients. Both analyses permitted
four-cluster solutions, and we found a weak but significant
degree of association between solutions. Examination of
external validity of the two solutions revealed stronger
associations with clinical variables for the Wechsler-scale-based
solution. The major conclusions were that the existence
of cognitive heterogeneity in schizophrenia exists across
a broad range of abilities, and appears to reflect a combination
of continuity of ability level and existence of possible
subtypes requiring further neuropsychological and neurobiological
verification. (JINS, 1998, 4, 353–362.)