Neuropsychiatric symptoms and activities of daily living in Alzheimer's disease: ALSOVA 5-year follow-up study

Abstract

Background: Neuropsychiatric symptoms (NPSs) in Alzheimer's disease (AD) are related to activities of daily living (ADLs), but longitudinal studies are sparse.

Objectives: We investigated which NPSs were related to decline in instrumental ADLs (IADLs) and basic ADLs (BADLs) in a 5-year follow-up of individuals with AD.

Methods: ALSOVA 5-year follow-up study data of 236 individuals with very mild or mild AD at baseline and their caregiver were analyzed. IADLs and BADLs were assessed with Alzheimer's Disease Cooperative Study ADL inventory, and NPSs with Neuropsychiatric Inventory at annual follow-up visits. Generalized estimating equations (GEEs) were used for longitudinal data analysis, and NPS-ADL networks were estimated to demonstrate symptom interactions.

Results: Apathy [rate ratio (RR) 1.23, 95% CI 1.06-1.44, p = 0.007], aberrant motor behavior (RR 1.24, 95% CI 1.07-1.44, p = 0.005), and appetite disturbances (RR 1.22, 95% CI 1.06-1.41, p = 0.005) were related to impairment in BADLs, and the same symptoms (RR 1.13, 95% CI 1.07-1.21, p < 0.001; RR 1.13, 95% CI 1.07-1.20, p < 0.001; RR 1.14; 95% CI 1.08-1.21, p < 0.001, for apathy, aberrant motor behavior, and appetite disturbances, respectively), in addition to delusions (RR 1.09, 95% CI 1.03-1.15, p = 0.004), were related to IADL impairment. Symptom networks varied at different time points.

Conclusion: As AD progresses, common (apathy) and uncommon NPSs (aberrant motor behavior, appetite disturbances, delusions) seem to be related to ADLs through various symptom interactions. Previous literature suggests that frontal pathology could underlie these relationships.

Keywords: Alzheimer’s disease; activities of daily living; behavioral and psychological symptoms of dementia; dementia; follow-up study; functional ability; network analysis; network structure; neuropsychiatric symptoms.