The problem with "problem behaviors": A systematic review of the association between individual patient behavioral and psychological symptoms and caregiver depression and burden within the dementia patient-caregiver dyad

Background: Behavioral and psychological symptoms of dementia (BPSDs) are routinely cited as important predictors of caregiver burden and depression. Although BPSDs include a wide variety of patient behaviors, they are routinely grouped together as one construct to differentiate them from cognitive symptoms of dementia. Determining the specific BPSDs that result in increased depression and burden for caregivers may elucidate the stress process for caregivers and facilitate the development of effective interventions for caregivers. Methods: We conducted a systematic review of English-language articles published from 1990 to 2010 to determine whether there are known symptoms or symptom clusters which exert undue negative impact on caregiver depression and burden. Additionally, we review systems used for classifying BSPD symptom clusters and determine whether there have been any mechanisms studied by which individual BPSD symptoms negatively affect caregivers. Finally, we examine how the role of timing of symptoms has been examined within the literature. Results: Thirty-five original research articles examined the impact of an individual behavior symptom on caregiver burden or depression/depressive symptoms. The studies had no consistent system for categorizing symptoms. Although depression, aggression, and sleep disturbances were the most frequently identified patient symptoms to impact negatively on caregivers, a wide range of symptoms was associated with caregiver burden and depression. Conclusions: The evidence is not conclusive as to whether some symptoms are more important than others. The studies reviewed were largely exploratory relative to the differential impact of individual BPSDs and did not focus on testing causal mechanisms by which specific symptoms exert more impact on caregiver mental health than others. Future research may benefit from the re-conceptualization of BPSDs from the perspective of their impact on the caregiver to examine hypothesis-driven differences among BPSD symptom clusters.