Aspects of Rest–Activity Rhythms Associated With Behavioral and Psychological Symptoms in Moderate and Severe Dementia

Abstract

Objective: Disturbances in rest–activity rhythms (RAR) are commonly observed in patients with dementia; however, the influence thereof on behavioral and psychological symptoms of dementia (BPSD) remains unexplored. This study aimed to determine whether there is an association between RAR and BPSD among patients with moderate and severe dementia. Methods: RAR analyses of 64 participants were performed using actigraphy. BPSD was assessed using the Neuropsychiatric Inventory-Nursing Home (NPI-NH) scale, and other clinical variables were assessed by the Mini-Mental State Examination, Cognitive Test for Severe Dementia, and Hyogo Activities of Daily Living Scale. Correlations among RAR, sleep time, and BPSD were analyzed. A stepwise multiple linear regression analysis was conducted to examine the association of RAR and sleep time with BPSD. The demographic variables were also adjusted. Variables were compared between two groups with aberrant and nonaberrant activity peak timing. Results: Correlation analysis showed that longer maximum durations of activity and shorter daytime sleep were associated with higher NPI-NH scores. Stepwise multiple linear regression analysis showed that maximum activity duration predicted the NPI-NH score after adjustment for the demographic variables. There was no significant difference in any variables between the groups with aberrant and nonaberrant activity peak timing. Conclusion: RAR is associated with BPSD in moderate-to-severe dementia, which should be considered with regard to treatment.