Neuropsychiatric symptom burden in early-onset and late-onset Alzheimer's disease as a function of age.

INTRODUCTION: We examined the burden of neuropsychiatric symptoms (NPSs) in early-onset (EO) and late-onset (LO) Alzheimer's disease (AD) and adjusted for age effects via the inclusion of cognitively unimpaired (CU) individuals. METHODS: Cross-sectional data from 2940 EOAD, 8665 LOAD, and 8775 age-stratified CU individuals (early-CU, n = 2433; late-CU, n = 6342) from the National Alzheimer's Coordinating Center database were included. Fisher's exact tests compared EOAD and LOAD on the presence and severity of NPSs. Multiple logistic regression models included an age*diagnosis interaction to examine age effects. RESULTS: Presence (ps < 0.0001) and severity (ps < 0.05) of NPS were greater in EOAD than in LOAD. However, after adjusting for base rates in NPS in CU individuals (age effects), only elation and eating behaviors were more frequent in EOAD (ps < 0.05) and nighttime behaviors more frequent and severe in LOAD (ps < 0.05). DISCUSSION: Few NPSs were specific to the EOAD versus LOAD. Previous findings of greater NPS burden in EOAD may partially reflect age effects. HIGHLIGHTS: Adjusting for age effect, elation and eating problems are more frequent in EOAD. Adjusting for age effect, sleep disturbances are more frequent and severe in LOAD. Age effects underlie higher neuropsychiatric symptom presentation in EOAD than in LOAD.

Accelerating diversity in Alzheimer's disease research by partnering with a community advisory board.

Introduction: Community advisory boards (CABs) and researcher partnerships present a promising opportunity to accelerate enrollment of underrepresented groups (URGs). We outline the framework for how the CAB and researchers at the Indiana Alzheimer's Disease Research Center (IADRC) partnered to accelerate URG participation in AD neuroimaging research. Methods: CAB and the IADRC researchers partnered to increase the CAB's impact on URG study enrollment through community and research interactions. Community interactions included the CAB collaboratively building a network of URG focused community organizations and collaborating with those URG-focused organizations to host IADRC outreach and recruitment events. Research interactions included direct impact (CAB members referring themselves or close contacts as participants) and strategic impact, mainly by the CAB working with researchers to develop and refine URG focused outreach and recruitment strategies for IADRC and affiliated studies to increase URG representation. We created a database infrastructure to measure how these interactions impacted URG study enrollment. Results: Out of the 354 URG research referrals made to the IADRC between October 2019 and December 2022, 267 referrals were directly referred by the CAB (N = 36) or from community events in which CAB members organized and/or volunteered at (N = 231). Out of these 267 referrals, 34 were enrolled in IADRC and 2 were enrolled in Indiana University Longitudinal Early Onset AD Study (IU LEADS). Of note, both studies require the prospective participants to be willing to do MRI and PET scans. As of December 2022, 30 out of the 34 enrolled participants have received a consensus diagnosis; the majority were cognitively normal (64.7%), with the remainder having mild cognitive impairment (17.6%) or early-stage AD (2.9%). Discussion: The IADRC CAB-researcher partnership had a measurable impact on the enrollment of African American/Black adults in AD neuroimaging studies. Future studies will need to test whether this conceptual model works for other sites and for other URGs.