0690 Greater variability of sleep disturbance is associated with executive functioning among people with schizophrenia

Abstract

Abstract Introduction Sleep disturbance is common among people with schizophrenia (PwS) and has been found to be related to poorer cognition in both PwS and non-psychiatric comparison participants (NCs). However, previous findings have been inconsistent on which aspects of executive functioning are most impacted by sleep. Additionally, the relationship of sleep variability to cognition in PwS has yet to be explored. This study aims to further understand the link between cognitive dysfunction and disturbed sleep in PwS and inform future sleep interventions to improve functioning and disability in PwS. Methods The current sample includes 36 participants (18 PwS, 18 NCs) from the San Diego area who completed executive functioning assessments (Delis-Kaplan Executive Function System, D-KEFS). Participants wore a wrist-worn Fitbit activity tracker for a 7-day period to monitor their sleep and activity. Independent samples t-tests were used to examine differences in mean and variability of sleep measures (total sleep time or TST, wake after sleep onset or WASO, and efficiency) and cognitive function between patients and controls. Spearman correlations were run to identify preliminary relationships between cognitive performance and sleep in both groups. Results The PwS and NCs were comparable on sex (50% female, age (mean 53 ± 10 years) and race (majority Caucasian). PwS and NCs were similar in mean sleep and variability of sleep measures. PwS had significantly poorer performance in all cognitive domains (p < 0.05). In the PwS, more variable WASO and sleep efficiency were significantly correlated with worse performance on visual-motor sequencing and motor speed tasks (rs = -0.56 to -0.66). Additionally, trending relationships were found between better executive function composite scores with both longer mean TST (rs = 0.43) and higher mean sleep efficiency (rs = 0.30) over the monitoring period. Data collection is ongoing, and updated results will be presented at the conference. Conclusion Poor sleep is a prominent problem in PwS and has been associated with deficits in various cognitive domains. The present study examines the relationships of mean and variability of sleep with executive functioning. Preliminary results found strong associations between worse and more variable sleep and cognitive performance that may strengthen as sample size increases. Support (If Any) National Institutes of Health [NIMH K23MH119375-01 (PI: Ellen E. Lee), NIMH R01MH094151-01 (PI: Dilip Jeste)]