Everyday functioning in young onset dementia: differences between diagnostic groups

BACKGROUND: The aim of this study was to examine differences in Instrumental Activities of Daily Living (IADL) among young-onset dementia (YOD) diagnoses. METHODS: Participants were included from Amsterdam Dementia and Longitudinal Early-Onset Alzheimer's Disease (LEADS) cohorts, with diagnoses of typical Alzheimer's disease (AD), behavioral variant frontotemporal dementia (bvFTD), primary progressive aphasia (PPA), posterior cortical atrophy (PCA), or dementia with Lewy bodies (DLB) established in multidisciplinary meetings. We compared overall IADL scores and item level scores between groups using multiple regression analyses, adjusted for cohort, demographics, and disease severity. RESULTS: We included 582 YOD patients (58.4 ± 4.2 years; 59%F), with overall moderate IADL problems (47.5 ± 8.57). DLB patients showed the most IADL difficulties (41.8 ± 7.8) compared to PCA, typical AD, bvFTD, and PPA (adjusted β range 4.62 to 14.14, all p < 0.01), whereas PPA patients showed the least IADL difficulties (55.8 ± 9.83), with item-specific differences. CONCLUSION: We found differences in everyday functioning between YOD types. Understanding IADL in YOD types will assist in care planning. Highlights: Patients with DLB showed the most IADL difficulties compared to PCA, typical AD, bvFTD, and PPA Patients with PPA showed the least IADL difficulties compared to DLB, PCA, typical AD, and bvFTD We identified diagnostic group-specific activity challenges. While ‘working’ was among the most commonly impaired activities across al groups, distinct functional challenges emerged per diagnosis: for example, DLB had high impairment in financial tasks, PCA patients in visual-spatial tasks, and bvFTD with planning and organizational activities (e.g. making appointments).