A-67: The Association Between Informant Characteristics and Neuropsychiatric Symptom Severity in Neurodegenerative Syndromes
Abstract
Objective: Neuropsychiatric symptoms are common in neurodegenerative syndromes, but assessment relies upon informant report, which may be susceptible to bias. This study examined whether Neuropsychiatric Inventory Questionnaire symptom severity (NPI-Q-SS) varies as a function of informant characteristics in Alzheimer’s dementia (AD), dementia with Lewy bodies (DLB), and Parkinson’s disease dementia (PDD). Method/Data Selection: Participants with AD (n=7,607; age=74.89±9.79; education=13.99±3.84), DLB (n=326; age=73.49±7.75; education=14.56±3.86), or PDD (n=113; age=72.89±7.49; education=15.12±3.69) from the National Alzheimer’s Coordinating Center dataset were included. Separate multiple linear regression models across groups evaluated whether informant age, sex, relationship to the participant, and co-residence predicted NPI-Q-SS, adjusting for participant demographics, global cognition (MMSE), and functional impairment (FAQ). Results/Data Synthesis: NPI-Q-SS scores were highest in DLB (8.10±5.74) relative to AD (5.05±4.85) and PDD (4.90±4.13). All models were statistically significant (p≤.001), explaining 13.3%, 12.7%, and 19.1% of the variance in AD, DLB, and PDD, respectively. In AD, younger informant age, female sex, and co-residence were modestly associated with higher NPI-Q-SS (β=−.071, .077, .056; all p<.001). In DLB, child informants reported higher NPI-Q-SS than spouses (β=.268; p<.05). No significant associations were observed in PDD. Conclusions: In AD, several informant characteristics were modestly associated with NPI-Q-SS, independent of cognitive and functional status. In DLB, a single association was observed, whereas no associations were found in PDD. Overall, informant context should be considered when interpreting NPI-Q-SS ratings, as effects may vary across diagnostic groups. Future research should further examine these relationships in larger samples, particularly in DLB and PDD.