Apathy and Emotional Blunting in Parkinson’s Disease

Abstract

Background: Apathy is common in Parkinson's disease (PD), even in the absence of dementia. In general, apathy has three key dimensions: emotional blunting, diminished initiative, and diminished interest. The objective of this study was to evaluate the clinical profile and impact of apathy in PD with particular emphasis on emotional blunting. Methods: 91 PD participants free of dementia were evaluated with the Apathy Inventory (IA). Those with clinically significant apathy (n=32) were compared to those without apathy (n=59) on clinical variables, level of disability, quality of life and caregiver burden. Within the apathy group, a subsequent comparison of those with apathy and emotional blunting (EB+; n=22) to those with apathy but no blunting (EB-; n=10) was undertaken. Results: In PD, compared to those without apathy, apathy sufferers were significantly more depressed, and had more impaired executive function, quality of life, and greater disability and caregiver burden. The EB+ group had worse quality of life and greater caregiver burden compared to the EB-group despite the EB-group being associated with older age and more advanced disease. Conclusion: In PD without dementia, apathy with emotional blunting has a greater adverse impact on the affected person and their caregiver than apathy without emotional blunting.