Daily Stressors and Adult Day Service Use by Family Caregivers: Effects on Depressive Symptoms, Positive Mood, and Dehydroepiandrosterone-Sulfate

Author(s): Zarit, S.H., Whetzel, C.A., Kim, K., Femia, E.E., Almedia, D.M., Rovine, M.J., Klein, L.C.

Published In: Am J Geriatr Psychiatr. 22(12):1592-602

Study Aim/Purpose: This study examined the effects of adult day service (ADS) use on caregiver relatives living with individuals with dementia (IWD) on the caregivers’ level of a salivary biomarker of stress reactivity as well as the association of the biomarker levels with variability in reported symptoms of positive mood and depression. 

Summary of Methods: This study used a “within-person withdrawal design” with a sample of 151 caregivers of IWD using ADS in 57 sites in northern and central New Jersey, the Philadelphia and Pittsburgh metropolitan areas, northern Virginia, and Denver, Colorado. For eight consecutive days―including days of ADS use and days of non-ADS use― researchers collected the following kinds of data: 1) saliva samples (5 per day) to determine daily levels of dehydroepiandrosterone-sulfate (DHEA-S); 2) self-reported levels of care-related and non-care related stressors and positive events; and 3) depressive symptoms and positive moods. The latter two were assessed during daily telephone interviews. Factors including age and gender of the caregiver, medications the caregiver was taking, duration of caregiving, the IWD’s ability to perform activities of daily living, and total days of ADS use over the study period were also included as between-person covariates in the statistical analysis. 

Summary of Key Results: Analysis found care-related stressors were lower on days the IWD attended ADS and that ADS use was associated with increased DHEA-S levels on days after ADS use (whether or not the person used ADS or not on those “days after ADS use”). The effect size was small but significant. They also found that days with positive moods were associated with the higher daily DHEA-S, though daily ADS use was not associated with reported positive moods. At the same time, total ADS days used was significantly related to higher mean positive moods. Daily depressive symptoms were not associated with daily DHEA-S. 

Study Limitations (as cited by authors): Although the authors suggest their “within-person withdrawal design” is a strong study design for examining the effects of an intermittent intervention such as respite, they also point out several limitations to their study including: 1) the fact that the sample were volunteers who were already using ADS may have selectively included those who experience a positive response to ADS; 2) the lack of measurement of duration of caregiver exposure to stressors; 3) the short study period; and 4) the predominance of women in the sample as the effects of DHEA-S levels differ by gender. 

Authors’ Discussion/Conclusions: The authors note that this is “one of the few studies demonstrating an effect of a caregiving intervention on physiologic indicators of stress.” While recognizing that effect size was small in this study, the authors suggest broadening the focus of evaluations of caregiver interventions “to include their impact on relevant biologic risk factors associated with chronic stress and disease.”