Morning Cortisol in Relation to Behavioral Symptoms of Nursing Home Residents With Dementia

Abstract

Behavioral symptoms of dementia (BSD) are a significant challenge for elders, their caregivers, and clinicians, with a prevalence ranging between 66% and 98%. Although several studies have examined BSD type and frequency, few studies have examined a possible neuroendocrine basis of BSD. The purpose of this study was to examine the association between morning cortisol levels and BSD in nursing home (NH) residents. Using a within-subject longitudinal design, saliva was collected four times daily for 5 days to obtain basal cortisol levels from 30 NH residents, aged 80 to 102. Behavior was observed every 20 min for 12 hr/day for 5 days. Mixed-model analysis was used to test the association between morning cortisol (MC) and BSD. To examine the association between MC and BSD across time, participants were divided into low (LM) and high morning (HM) cortisol groups. A significant inverse association between mean overall BSD and morning cortisol (F = 12.71, p = .000) was found. A significant inverse association between low and high morning cortisol and behavior variability across time (F = 15.36. p = .000) was found. The LM group exhibited significantly more behavioral variability across the day than the HM cortisol group. There was a significant group difference between two co-occurring behaviors, vocalization, and restlessness (F = 19.59, p = .000). Although preliminary, these results suggest an association between morning cortisol and BSD. Low morning cortisol, potentially indicating HPA axis dysregulation, may increase vulnerability to BSD.