Subtype diagnosis in schizophrenia and its relation to neuropsychological and computerized tomography measures.

We compared schizophrenic patients with a subtype diagnosis of paranoia (n = 14) to those with nonparanoid subtype diagnoses (n = 18) on the Wisconsin Card Sorting Test (WCST) and multiple computed tomography (CT) scan measures. The results showed that patients with nonparanoid diagnoses sorted fewer categories and made more perseverative errors on the WCST than did patients with the paranoid diagnosis. However, patients in the nonparanoid group could not be distinguished from those in the paranoid group on CT scan measures of brain structure. Additionally, a significant correlation was found between right frontal sulcal enlargement on CT scans and the number of perseverative errors made on the WCST.