Systematic reviews on behavioural and psychological symptoms in the older or demented population

Abstract

Introduction: Behavioural and psychological symptoms of dementia (BPS) include depressive symptoms, anxiety, apathy, sleep problems, irritability, psychosis, wandering, elation and agitation, and are common in the non-demented and demented population.

Methods: We have undertaken a systematic review of reviews to give a broad overview of the prevalence, course, biological and psychosocial associations, care and outcomes of BPS in the older or demented population, and highlight limitations and gaps in existing research. Embase and Medline were searched for systematic reviews using search terms for BPS, dementia and ageing.

Results: Thirty-six reviews were identified. Most investigated the prevalence or course of symptoms, while few reviewed the effects of BPS on outcomes and care. BPS were found to occur in non-demented, cognitively impaired and demented people, but reported estimates vary widely. Biological factors associated with BPS in dementia include genetic factors, homocysteine levels and vascular changes. Psychosocial factors increase risk of BPS; however, across studies and between symptoms findings are inconsistent. BPS have been associated with burden of care, caregiver's general health and caregiver depression scores, but findings are limited regarding institutionalisation, quality of life and disease outcome.

Conclusions: Limitations of reviews include a lack of high quality reviews, particularly of BPS other than depression. Limitations of original studies include heterogeneity in study design particularly related to measurement of BPS, level of cognitive impairment, population characteristics and participant recruitment. It is our recommendation that more high quality reviews, including all BPS, and longitudinal studies with larger sample sizes that use frequently cited instruments to measure BPS are undertaken. A better understanding of the risk factors and course of BPS will inform prevention, treatment and management and possibly improve quality of life for the patients and their carers.

Figure 1

Populations and BPS that were the focus of the reviews.

Figure 2

Overview of the recommendations and limitations reported by the included reviews. In total, 36 reviews were included in the review of reviews. Only recommendations and limitations reported by three or more reviews are included in the figures. Reviews that make multiple recommendations or limitations may be included more than once.

Figure 3

Number of reviews that reported on each symptom by the topic of the review. Agg, aggression; Agi, agitation; Anx, anxiety; BPS, behavioural and psychological symptoms; Dep, depressive symptoms; Ela, elation; Psy, psychosis; Sle, sleep problems; Wan, wandering; In total 36 reviews were included in the review of reviews. Reviews that report on multiple topics or more than one BPS are included more than once.