Clinical correlates associated with cognitive dysfunction in people with schizophrenia.

Aims: The purpose of the present study was to investigate the correlation between cognitive function and clinical variables in people with schizophrenia.

Methods: The subjects were 61 stabilized outpatients with schizophrenia (DSM-IV). Their mean age was 40.1 (SD = 12.2) years. All subjects gave written informed consent to participate in the research. Cognitive function was evaluated using the Brief Assessment of Cognition in Schizophrenia. Clinical symptoms were assessed using the Positive and Negative Syndrome Scale, the Calgary Depression Scale for Schizophrenia, and the Drug-Induced Extrapyramidal Symptoms Scale.

Results: The Positive and Negative Syndrome Scale Negative syndrome score was significantly correlated with verbal memory score (r = -0.37, P < 0.01), working memory score (r = 0.38, P < 0.01), attention and speed of information processing score (r = -0.51, P < 0.01), verbal fluency score (r = -0.39, P < 0.01), and composite score (r = -0.54, P < 0.01). In addition, the Drug-Induced Extrapyramidal Symptoms Scale score was significantly correlated with attention and speed of information processing (r = -0.45, P < 0.01), and composite score (r = -0.41, P < 0. 01). Dose of antipsychotics and anti-Parkinson drugs was not significantly correlated with the Brief Assessment of Cognition in Schizophrenia scores.

Conclusions: These results indicate that cognitive dysfunction of people with schizophrenia might be associated with negative and drug-induced extrapyramidal symptoms, suggesting that their minimization would be important for improving cognitive dysfunction.