Linguistic and cognitive failures in schizophrenia. A multivariate analysis.

Schizophrenic (N = 38), manic (N = 30), and normal (N = 25) subjects were examined with laboratory tasks measuring serial recall and encoding, distractibility, and reality monitoring. In addition, the psychiatric patients were examined with three measures of verbal communication disorder, including positive thought disorder, negative thought disorder, and frequency of reference failures. It was found that positive thought disorder and reference failures in schizophrenics were best predicted by measures of distractibility and reality monitoring, with communication disorder in mania, although common and severe, not predicted by these cognitive performance measures. Furthermore, negative thought disorder in schizophrenics was not predicted by the cognitive measures. These results are discussed in terms of their implications regarding the differences in potential determinants of positive and negative thought disorders.