A – 121 Associations of Dimensional Apathy, Mood, and Cognition with Quality of Life in Parkinson's Disease

Abstract Objective Non-motor symptoms (NMSs) in Parkinson’s disease (PD) are prevalent and associated with reduced quality of life (QoL). Apathy, cognition, and mood are NMSs with established connections to QoL; however, the relative contributions of apathy dimensions to QoL have not been clearly defined. This study examined apathy dimensions in PD patients, evaluating their impact on QoL when accounting for mood and cognition. Method 43 non-demented adults with PD were included in the current sample. Motor severity was assessed via the MDS-Unified Parkinson’s Disease Rating Scale Part III score (MDS-UPDRS III). Patients completed the Dimensional Apathy Scale (DAS), General Anxiety Disorder-7 (GAD-7), Beck Depression Inventory-II (BDI-II), Parkinson’s Disease Questionnaire-39 (PDQ-39; QoL measure), and a neuropsychological battery. A cognitive composite was created by calculating mean within-individual performance across cognitive tests. Results Hierarchical regression analyses were conducted. GAD-7, BDI-II, cognition, and MDS-UPDRS III score were first entered into the model, explaining 53% of the variance in QoL (p < 0.001). Adding DAS total score accounted for an additional 9% of the variance (ΔR2 = .088, p = 0.026), with greater apathy associated with lower QoL (β = 0.396, p = 0.026). Secondary analyses using hierarchical regression with DAS subdomains indicated that this relationship was driven by the DAS Executive, rather than DAS Emotional or DAS Behavior/Cognition subdomains. Conclusion This study demonstrated that apathy, particularly executive apathy, is associated with QOL in PD even when accounting for effects of mood, cognition, and motor symptom severity. Results highlight the importance of clinically assessing specific apathy features in patients with PD.