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


Table 1 presents demographic and clinical baseline variables. NPI and ADL scores were higher in LBD compared with AD (both P values <.001). The number of participants completing the follow-up assessments is shown in the Supplementary Figure S1. The vast majority of dropout was due to death. The average follow-up time was 3.86 years: 4.23 years for AD and 3.37 years for LBD. Figure 1 shows the average curve of the functional scores over time. The impairment was consistently more severe in LBD than AD (P < .001), but the trajectories did not differ. Figure 2 shows the functional decline trajectory in the different NPI quartiles in AD and LBD.

Figure 1.

Activity of daily living (ADL) marginal estimated curves for Alzheimer's disease (AD) (dashed lines) and Lewy body dementia (LBD) (dotted lines). Vertical bars at the bottom represent the observations used to adjust the models. Each curve represents the estimation of the marginal functional trajectory during the observed time for AD and LBD. The LBD curve is significantly greater than the AD curve (P = .0005).

Figure 2.

Functional decline trajectories estimated by Neuropsychiatric Inventory (NPI) longitudinal score quartiles. (A) The estimation of the marginal functional trajectories for people living with Alzheimer's disease (AD). (B) The estimation of the marginal functional trajectories for people living with Lewy body dementia (LBD). (C) The marginal activity of daily living (ADL) total score estimation by each NPI quartile for AD and LBD groups, and the total population. All model estimations have been adjusted by Mini-Mental State Examination score, age, sex, and comorbidity.

Baseline NPI Total Scores as Predictors of Functional Trajectories

In the linear mixed-effects model, for AD, people in the second quartile (estimate = 0.179; standard error (SE) = 0.089; P = .047) and fourth quartile (estimate = 0.276; SE = 0.099; P = .006) had significant associations with increased functional impairment, compared with the first quartile. There were no significant associations in the LBD group (Table 2).

Longitudinal Associations Between NPI Total Scores and Functional Trajectories

NPI score longitudinal course was significantly associated with functional decline in both groups. In AD, people in the fourth quartile (estimate = 0.228; SE = 0.060; P < .001), and for LBD, people in the third quartile (estimate = 0.214; SE = 0.093; P = .023) and fourth quartile (estimate = 0.289; SE = 0.097; P = .003) had more functional impairment compared with the first quartile. Likewise, for the combined model: third quartile (estimate = 0.127; SE = 0.048; P = .007) and fourth quartile (estimate = 0.249; SE = 0.052; P < .001) (Table 3).