Neuropsychological performance and brain morphology in sib-pairs discordant for schizophrenia

In this study we investigated the relationships between cognitive function, assessed by means of Wechsler Adult Intelligence Scale-Revised (WAIS-R) and Wisconsin Card Sorting Test (WCST), and brain morphological abnormalities, evaluated by means of Magnetic Resonance Imaging (MRI), in 8 sib-pairs discordant for schizophrenia. Affected siblings showed a significantly worse performance at the three global scores of WAIS-R considered in the study (Full-scale IQ, Verbal IQ, Performance IQ) and, similarly, a trend for a worse performance at the item 'number of categories completed' of the WCST. As for WAIS in each one of the sib-pairs Full-scale IQ score was able to discriminate between the affected and the unaffected sibling, showing lower values in schizophrenic patients. No correlation was found between brain morphological features and neuropsychological performance both at WAIS-R and at WCST.