Determinants of behavioral and psychological symptoms of dementia: A scoping review of the evidence

Highlights

• Interventions for dementia symptoms rely on identification of their determinants.

• Patient, caregiver, and environmental determinants of symptoms are identified.

• Little evidence for caregiver and environmental determinants was found.

• Research gaps include lack of consistent measures and longitudinal data for symptoms.

• Policy implications reflect goals of the National Alzheimer's Project Act.

Abstract

Background

Behavioral and psychological symptoms of dementia (BPSD) are prevalent in people with neurodegenerative diseases.

Purpose

In this scoping review the Kales, Gitlin and Lykestos framework is used to answer the question: What high quality evidence exists for the patient, caregiver and environmental determinants of five specific BPSD: aggression, agitation, apathy, depression and psychosis?

Method

An a priori review protocol was developed; 692 of 6013 articles retrieved in the search were deemed eligible for review. Gough’s Weight of Evidence Framework and the Cochrane Collaboration’s tool for assessing risk of bias were used. The findings from 56 high quality/low bias articles are summarized.

Discussion

Each symptom had its own set of determinants, but many were common across several symptoms: neurodegeneration, type of dementia, severity of cognitive impairments, and declining functional abilities, and to a lesser extent, caregiver burden and communication.

Conclusion

Research and policy implications are relevant to the National Plan to Address Alzheimer’s Disease.

Introduction

Worldwide, 47.5 million people have dementia, a clinical syndrome caused by a number of neurodegenerative diseases (World Health Organization, 2016). The vast majority of these individuals exhibit behavioral and psychological symptoms of dementia (BPSD), which are distressing perceptions, thought content and mood, and behaviors such as aggression and apathy (Kales, Gitlin, Lyketsos, & Detroit Expert Panel on Assessment Management of Neuropsychiatric Symptoms of Dementia, 2014). BPSD result in precipitous declines in function, risk for physical abuse, poor quality of life, caregiver burden, and they account for more than one-third of all dementia-related costs (Adelman et al., 2014, Herrmann et al., 2006, Toot et al., 2017). Although national and international efforts have resulted in progress toward humanizing dementia care, BPSD continue to be treated mainly with antipsychotic drugs and other restraining methods that result in excess mortality, falls, and social isolation from the sedating effects of these drugs (Wunderlich & Kohler, 2000). This is in spite of Food and Drug Administration warnings about antipsychotic medications and consistent recommendations from experts in leading geriatric organizations that call for the use of nonpharmacologic approaches as the first line of treatment (American Geriatrics Society & American Association for Geriatric Psychiatry, 2003).

The effectiveness of any treatment for BPSD relies on accurate identification of the precipitating cause(s) or determinant(s) of the symptom, which then become the target of intervention (Kales, Gitlin, & Lyketsos, 2015). Neurodegeneration has been a primary target of pharmaceutical research, but there are other factors that contribute to BPSD (Casanova, Starkstein, & Jellinger, 2011). Nursing science has a rich history of conceptualizing BPSD as expressions of unmet needs within frameworks, where a number of pathophysiologic, psychological, and environmental determinants are hypothesized to underlie BPSD (Algase et al., 1996, Hall and Buckwalter, 1987). These frameworks have guided research but rarely have large effect sizes been demonstrated for the interventions derived from them (Livingston et al., 2014). Pharmaceutical treatments directed at pathophysiologic targets have also shown disappointing effects.

A recent framework for BPSD is that conceptualized by Kales et al. (2015). Figure 1 illustrates their model, which builds on prior frameworks and the advances made in neuroscience, genetics, and caregiving during the past 20 years. Importantly, this framework provides a more comprehensive range of potential patient, caregiver, and environmental determinants of BPSD than was available in the past. The identification of determinants of BPSD is needed for the development of efficacious person-centered interventions. Rather than mask BPSD, which may be the individual's only method for communicating distress, interventions designed around evidence-based determinants target their root cause.

BPSD include many different symptoms often measured inconsistently and imprecisely as one construct. In the past, few systematic reviews have focused on individual clinical symptoms but more commonly their aggregate. Anticipating that the literature on individual symptoms would be complex and heterogeneous, we conducted a scoping review, as opposed to a systematic review. In this approach, the existing evidence base for individual symptoms is examined regardless of the heterogeneity of the literature, key determinants are identified, the quality of evidence is evaluated, and gaps in research are identified—all objectives of scoping reviews (Peters et al., 2015). Thus, the aim of this scoping review was to use the framework developed by Kales et al. (2015) to answer the question: What high-quality evidence exists for the patient, caregiver, and environmental determinants of five specific BPSD: aggression, agitation, apathy, depression, and psychosis?

This scoping review is the outcome of a presummit activity of the 2017 National Research Summit on Dementia Care: Care and Services for Persons with Dementia, Family Members and Caregivers (https://aspe.hhs.gov/report/national-plan-address-alzheimers-disease-2016-update). To that purpose, we conclude with a discussion of broad research and policy implications that are informed by the review and discussed at the National Summit.