Effects of ziprasidone and risperidone on cognitive inhibition function through visual pathway of patients with paranoid schizophrenia

Objective To explore the effects of ziprasidone and risperidone on cognitive inhibition function through visual pathway of patients with paranoid schizophrenia. Methods In the open-label, flexible-dosage trial, 124 patients with paranoid schizophrenia were randomly divided into ziprasidone group(120-160 mg/d)and risperidone group(4-8 mg/d) for treatment of 8 weeks. They were assessed with computerized Color Word Test(CWT) and Continuous Performance Test(CPT) through visual pathway for cognitive inhibition function, Positive and Negative Syndrome Scale for efficacy on baseline and 8th weekend. Results After treatment with ziprasidone, the error number (3.12±5.23), the time per correct answer((1.92±1.38)s) of CWT, as well as the double-digit mistaken number (2.31±3.76)and the three-figure mistaken number(3.15±2.80) of CPT reduced more than those before medication ((4.60±6.80), ( 2.74±1.52 )s, (3.85±3.62), (4.42±3.53)) (P<0.05). In risperidone group, the double-digit mistake number of CPT(3.39±3.59) after pharmacotherapy reduced more than that before pharmacotherapy(4.23±3.88) (P<0.05). After treatment the time per correct answer of CWT and the mistaken numbers of CPT in ziprasidone group were less than those in risperidone group(P<0.05), meanwhile, the scores of PANSS in two groups were significantly lower than those before treatment (P<0.01). Conclusion It is effective for ziprasidone and risperidone to improve the function of cognitive inhibition on patients with paranoid schizophrenia, but there is more dramatic for ziprasidone in short-term treatment. Key words: Ziprasidone; Risperidone; Paranoid schizophrenia; Cognitive inhibition