A-02: Neuropsychiatric Symptoms Predict Functional Disability Across Parkinsonian Disorders

Abstract

Objective: Neuropsychiatric symptoms (NPS) are common across parkinsonian disorders. Symptom profiles vary by diagnosis and stage of disease, and individual symptoms may differentially affect everyday functioning. We evaluated the impact of NPS on functional status in Parkinson’s disease (PD), Lewy body disease (LBD), progressive supranuclear palsy (PSP), and corticobasal degeneration (CBD), stratifying by dementia status for each diagnosis. Method/Data Selection: Data were obtained from the National Alzheimer’s Coordinating Center (NACC) Uniform Data Set Version 3.0. Participants with PD, LBD, PSP, and CBD were included for analysis and stratified by dementia status. Functional impairment was measured using the Functional Activities Questionnaire (FAQ), while neuropsychiatric symptom severity was assessed using the Neuropsychiatric Inventory Questionnaire (NPI-Q). Results/Data Synthesis: Regression analyses were conducted to evaluate the effect of NPS on total FAQ scores for each diagnostic group, covarying for age and education. Higher NPS burden predicted greater functional impairment across all groups, except for PSP with dementia. Apathy emerged as a unique predictor of functional impairment in dementia groups, while depression emerged as a unique predictor of functional impairment in groups without dementia. Conclusions: Neuropsychiatric symptoms show distinct relationships with functional impairment across parkinsonian disorders, with mood symptoms more closely related to impairment prior to dementia and motivational deficits becoming more prominent once dementia develops. These findings support the distinction between motivational and mood syndromes and highlight apathy and depression as clinically meaningful contributors to functional decline in parkinsonian disorders.