Abstract: Objective  To compare the clinical effects of zopiclone and clonazepam in the treatment of schizophrenia and sleep disorders. 
Methods  In total, 94 patients with schizophrenia complicated by sleep disorders were selected as the research subjects, and they were all given conventional treatment. The patients were divided into zopiclone group and clonazepam group by the random number table method. Zopiclone group and clonazepam group were treated with zopiclone and clonazepam respectively. The therapeutic efficacy, sleep electroencephalogram parameters and nerve electrophysiological indicators were compared between two groups, and positive and negative symptom scale (PANSS) and repeatable battery for the assessment of neuropsychological status (RBANS) were used to evaluate the severity of schizophrenia symptoms and cognitive function before and after treatment. The occurrence of drug-related adverse reactions during treatment were statistically analyzed. 
Results  There was no significant difference in the total effective rate between two groups (P＞0.05) as well as in scores of items of PANSS between two groups after treatment (P＞0.05). After treatment, the amplitudes of P300 and N2-P3 in zopiclone group were greater than those in clonazepam group, and the duration of S3 phase of sleep electroencephalogram was longer than that in clonazepam group (P＜0.05). The RBANS scores of attention and delayed memory in zopiclone group after treatment were higher than those in clonazepam group (P＜0.05). The incidence rates of somnolence and myotonia were higher in clonazepam group than in zopiclone group (P＜0.05). 
Conclusion  In the treatment of schizophrenia and sleep disorders, zopiclone, as compared with clonazepam, can more effectively prolong the S3 phase of sleep electroencephalogram, improve the electrophysiological status of brain nerve, enhance the cognitive function, and reduce the incidence rates of adverse reactions, but both drugs have similar effects on mental status of patients. 

Key words: schizophrenia, sleep disorders, zopiclone, clonazepam