Behavioral and psychological symptoms of dementia and caregivers' stress appraisals: intra-individual stability and change over short-term observations.

Dementia is commonly associated with memory loss, but Behavioral and Psychological Symptoms of Dementia (BPSD) such as disruptive behaviors, agitation, and problems with mood, usually have a more significant impact on caregivers' stress. It is known that BPSD and caregivers' stress reactions vary in frequency over the long-term course of dementia, however little is known about the variability over the short-term. The current study included 85 people with dementia and their primary caregivers assessed over three months. Caregivers used a 24-hour log on multiple, consecutive days to report behavioral symptoms of dementia on seven domains of behavior, as well as their stress reactions for each domain. Using latent growth curve analysis, most BPSD and caregiver stress appraisals were found to be, on average, stable over the three-month time frame. For many BPSD and stress appraisal models, however, intra-individual differences in rate of change were significantly different from the mean trend, indicating behaviors and stress are not stable over three months when assessed at the level of the individual. Covariates were used to explain individual differences in rates of change; however few variables were significantly associated with intra-individual short-term change over time.