Neuropsychiatric Symptoms and Functional Decline in Alzheimer's Disease and Lewy Body Dementia

Miguel Germán Borda, MD; Dag Aarsland, MD, PhD; Diego Alejandro Tovar-Rios, MSC; Lasse M. Giil, MD, PhD; Clive Ballard, MD, PhD; Maria Camila Gonzalez, MD; Kolbjørn Brønnick, PhD; Guido Alves, MD, PhD; Ketil Oppedal, PhD; Hogne Soennesyn, MD, PhD; Audun Osland Vik-Mo, MD, PhD


J Am Geriatr Soc. 2020;68(10):2257-2263. 

In This Article

Abstract and Introduction


Background/Objectives: Functional status is one of the most important markers of well-being in older adults, but the drivers of functional decline in dementia are not well known. The aim of our work was to study the association of neuropsychiatric symptoms (NPSs) with functional decline over 5 years in newly diagnosed people with Alzheimer's disease (AD) and Lewy body dementia (LBD).

Design: Secondary analysis of the Dementia Study of Western Norway longitudinal cohort study.

Setting: Multicenter study conducted in memory clinics in western Norway.

Participants: We included a total of 196 patients newly diagnosed with AD (n = 111) and LBD (n = 85), followed up annually for 5 years.

Main Outcomes and Measures: The outcome was the rapid disability rating scale (items 1–13). Linear mixed-effects models were used for analysis with the total score of the Norwegian Neuropsychiatric Inventory (NPI) as a predictor measured either at baseline or longitudinally, adjusted for potential confounders, including cognition. Effect modification was checked by introducing interactions with NPI score and stratifying by diagnosis.

Results: The total NPI score longitudinal course was associated with functional decline in both AD and LBD. At baseline, the total NPI score predicted functional decline in AD.

Conclusion: NPSs were associated with the rate of functional decline in people with AD and LBD, independent of cognitive impairment. These results highlight the relevance of early detection and intervention of NPSs, which may also reduce functional decline. J Am Geriatr Soc 68:2257–2263, 2020.


Proper everyday functioning is important for the well-being, independence, and quality of life in older adults.[1–3] Impairment in activities of daily living (ADLs) increases the need for health and social care due to its tendency to generate dependency.[4] Therefore, maintaining functional status has become an important goal in geriatrics and gerontology, since most diseases, syndromes, and unfavorable conditions that affect older adults' health have the loss of function as a shared outcome.

In dementia, functional status is of utmost importance regarding diagnosis, staging, and prognosis.[5,6] In dementia, the loss of function is assumed to be mainly driven by cognitive loss. However, there are many other problems that may play an important role.[7]

Neuropsychiatric symptoms (NPSs) are prevalent in Alzheimer's disease (AD) and Lewy body dementia (LBD),[8,9] the two most common neurodegenerative dementias. NPSs are more frequent in patients with comorbidity, polypharmacy, adverse effects of medication, malnutrition, institutionalization, mobility limitations, and falls, leading to worse prognosis, increased morbidity, and mortality.[10–12]

In people living with LBD, NPSs, comorbidity, frailty, and functional impairment are more frequent and severe than for people with AD.[8,13,14] These characteristics make this group more prone to dependency and to a worse prognosis when compared with other common dementias.[13,14] Little is known regarding the impact of the total NPS burden on the functional trajectories in people living with dementia. Previous studies in AD report associations with hallucinations, delusions, apathy, and aggression, but findings are not conclusive.[10,15–17] In particular, the effect of the total load of NPSs has not been studied, and even less is known in those diagnosed with LBD. Potential interventions for detecting, treating, and controlling NPSs could help to improve functional prognosis. Thus, the aim of the current study is to explore the associations between longitudinal trajectories of functional decline and the total load of NPSs.