Relationship between symptom dimensions and neurocognitive functioning in schizophrenia: a meta-analysis of WCST and CPT studies

Cognitive deficits have been hypothesized to be differentially related to t he negative, positive and disorganization dimensions of schizophrenia sympt oms. In this article, we quantitatively review the published literature on the relationships between symptom dimensions in schizophrenia and performan ce on the two most widely applied tests of executive functioning and sustai ned attention, the Wisconsin Card Sorting Test (WCST) and the Continuous Pe rformance Test (CPT). Meta-analyses were conducted on studies that reported correlational data for the relations between performance on these tests an d scales of positive and negative symptoms. The more recent distinction bet ween disorganization and reality distortion was also taken into account. Th e results showed statistically significant relationships of negative sympto ms with worse performance on the WCST and the CPT. Disorganization symptoms showed a significant positive correlation with perseverations on the WCST, but not with CPT performance. in contrast, reality distortion symptoms and general scores for all positive symptoms did not correlate with either mea sure. Although some correlations were statistically significant, the observ ed associations between psychiatric symptoms and cognitive performance were typically weak, suggesting relative independence of these disease processe s. (C) 2001 Published by Elsevier Science Ltd.