The relationship between objective sleep variables and subjective sleep estimation in schizophrenia

AIM: Few investigations of sleep structure in schizophrenia have concentrat ed on the relationship between objective and subjective sleep variables, Th e aim of this study was to assess objective sleep variables ann subjective estimation of sleep duration and sleep quality. METHODS: Polysomnography was performed in 20 chronic patients with schizoph renia during three consecutive nights. After final awakenings subjects answ ered questions concerning subjective estimations of sleep duration, sleep l atency, number of awakenings, and sleep depth. Pearson correlations between ranged subjective reports and objective sleep variables were performed. RESULTS: The results showed a high positive correlation between objective s leep latency ann its subjective estimation; a positive correlation between subjective estimation of sleep depth ann percentage of slow wave sleep (SWS %); a positive correlation between eye movement (EM) density and subjective estimation of wakefulness during the night, and a negative correlation bet ween EM density and dream reports. CONCLUSION: We concluded that objective sleep variables ave related to subj ective sleep Estimation in schizophrenic patients. In these patients, Ehl a ctivity in REM sleep is related to the subjective feeling of wakefulness.