Prevalence and cognitive correlates of sleep problems in Chinese patients with first-episode drug-naïve schizophrenia

BACKGROUND: Sleep problems (SPs) frequently occur in patients with schizophrenia patients experiencing cognitive impairments. Thus, this study aimed to investigate the association between SPs and first-episode drug-naive schizophrenia (FDS), and to examine the impact of SPs on their cognitive function. METHODS: In this cross-sectional study, we enrolled 291 FDS patients (non-SPs/SPs = 197/94) and 685 subjects from the general population (GP, non-SPs/SPs = 577/108) according to the DSM-IV and Pittsburgh Sleep Quality Index (PSQI) grouping. Cognition and sleep quality of subjects were assessed using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) and the PSQI, respectively. RESULTS: Compared to GP subjects, patients with FDS had a significantly higher prevalence of SPs (15.77% versus 32.30%, OR = 2.55, p < 0.001) and a significantly higher total score of PSQI (p < 0.001). After adjusting for covariates, the visuospatial/constructional score of SPs was significantly lower than that of non-SPs in patients with FDS (p < 0.05), and all RBANS scores of patients with FDS were significantly lower than those of GP subjects, with or without SPs (p < 0.001), excepted for the visuospatial/constructional score. Pearson correlation and linear regression analyses showed a negative association between the total PSQI score and the visuospatial/constructional score in patients with FDS (p < 0.05). CONCLUSIONS: Our findings confirm a significant association between SPs and FDS. Notably, the presence of SPs in patients with FDS is linked to more severe visuospatial/constructional impairments, suggesting that targeting sleep quality might help mitigate this specific cognitive impairment. CLINICAL TRIAL NUMBER: Not applicable.