The effects and relevance of sleep on memory consolidation in patients with stable paranoid schizophrenia

Abstract

Objective To explore the memory function and the effects of sleep on memory consolidation in patients with stable paranoid schizophrenia. Method Sixty patients with stable paranoid schizophrenia were randomly assigned into research group(n=30) and control group(n=30).30 healthy people were raised as a healthy control group.The polysomnography (PSG) was used for 10 hours of sleep monitoring in the research group and the healthy control group and the multiple memory assessment scale(MMAS) was used to test the subjects memory before and after the sleep monitoring.Control group performed memory tests in equal length daytime.Pre-test and post-memory measurements were compared. Results The pre-memory test of three groups had significant statistical differences (F(2, 87)=31.40, 39.89; P 0.05) .But compared with the control group, auditory verbal memory conservation rate((62.64±9.06)% vs (43.00±9.73)%, P<0.01), recognition accuracy rate ((69.11±11.04)% vs (61.78±11.67)%, P<0.05), picture memory conservation rate((71.20±14.95)% vs (58.72±16.19)%, P<0.01), recognition accuracy rate ((86.89±8.02)% vs (78.89±12.63)%, P<0.01) of the research group showed statistical significance differences (P<0.05). Both N2 (r=0.377, P<0.05) and REM(r=0.436, P<0.05) had positive correlation with recognition accuracy rate of auditory verbal memory in research group. Conclusion Stable paranoid schizophrenic patients have poorer memory function(auditory verbal words memory recall, picture memory recall) than healthy people.Sleep promotes the consolidation of memory in patients with schizophrenia.Both N2 and REM of patients with stable paranoid schizophrenic have positive correlation with recognition accuracy rate of auditory verbal memory. Key words: Paranoid; Schizophrenia; Sleep; Memory consolidation