Study On The Correlation Between Quality Of Sleep And Cognitive Function In Patients With First Episode Schizophrenia

Objective Cognitive dysfunction is an important factor of functional impairment in patients with schizophrenia.In clinical practice,patients with schizophrenia are often accompanied by sleep disturbances.Previous studies have found that sleep disorders are correlated with cognitive impairment.However,most of the studies included patients with chronic schizophrenia or those with stable treatment with drugs,and the influence of drugs on sleep and cognition could not be excluded recently.So this study was proposed to explore the effects of poor sleep quality on 7 cognitive domains in patients with first-episode schizophrenia or schizophrenic disorder,in order to provide evidence for the pathogenesis of schizophrenia and find new therapeutic targets.Methods According to the inclusion and exclusion criteria,sixty-one patients with first episode schizophrenia or schizophrenic disorder were recruited in a cross-sectional study.Pittsburgh Sleep Quality Index(PSQI)?Positive and negative symptoms scale(PANSS)?Global Assessment of Functioning(GAF)?MATRICS Consensus Cognition Battery(MCCB)was used for assessment.The PSQI was used to asscess the sleep of quality among them,all subjects were divided into two groups,one was poor sleep quality with PSQI total score greater than 7,another was good sleep quality with PSQI total score less than or equal to 7.The PANSS was used to assess the severity of symptoms,the higher the score of PANSS,the greater the severity of the mental symptoms.The GAF was used to assess the function of patients,the lower the score,the greater the functional impairment.The MCCB was used to evaluate the cognitive function of patients.It mainly includes seven cognitive domains: information processing speed,attention/alertness,working memory,word learning,visual learning,reasoning and problem solving,and social cognition.The lower the score,the greater the cognitive impairment.The reasearchers were trained on the research scheme,sample collection method,various scales` assessment and the use of cognitive assessment tools.Two graduate students were responsible for the assessment of scales and cognitive function,and the study was conducted after the scales reached the consistency standard.Results There was no significant difference in gender,marriage,familyhistory,age,years of education,PANSS total scord,positive,negative,activation,autistic preoccupation and GAF between the two groups(P>0.05).The difference of dysphoric mood between the group with poor sleep quality and group with good sleep quality was statistically significant [(10.34±4.15)VS(8.41±3.15),P=0.043],in other words,dysphoric mood were more serious in the group with poor sleep quality.The scores of category fluency in the processing speed and visual learning in poor sleep quality were significantly lower than that in good sleep quality[(31.4±11.8)VS(42.4±13.7),P=0.002]?[(37.75±7.027)VS(43.03±10.031),P=0.023],that is to say,the cognitive function of the poor sleep quality group was worse than that of the good sleep quality group.The visual learning domain was negatively correlated with PSQI(r=-0.323,P<0.05),and the sleep time in PSQI was negatively correlated with visual learning domain(r=-0.371,P<0.01).Conclusion 1 The sleep quality of schizophrenic patients may be related to the sympotoms of dysphoric mood,but the sleep problems of schizophrenic patients are not caused by anxiety and depression.2 There was a relationship between sleep quality and category fluency and visual learning in patients with schizophrenic.3There is a correlation between the sleep quality and the cognitive function in patients with schizophrenia.The worse the sleep quality is,the more severe the cognitive function impairment is in the visual learning field.Further analysis shows that the visual learning field is mainly correlated with the sleep time in PSQI.