Reduced Empathy Scores in Patients with Parkinson's Disease: A Non-Motor Symptom Associated with Advanced Disease Stages

Background: Empathy describes the ability to infer and share emotional experiences of other people and is a central component of normal social functioning. Impaired empathy might be a non-motor symptom in Parkinson's disease (PD). Objective: To examine empathic abilities and their relationship to clinical and cognitive functioning in PD patients. Methods: Empathy was measured in 75 non-demented PD patients and 34 age-matched healthy controls using a German version of the Interpersonal Reactivity Index. Moreover, we collected demographic and clinical data and conducted a comprehensive neuropsychological test battery. Results: PD patients had a significant lower global empathy score than healthy controls. Furthermore, we found significant group differences for the cognitive empathy scales but not for the scales which are sensitive for affective empathy components. The empathy decrease was significantly higher in advanced Hoehn & Yahr stages. There were only sporadic significant correlations between empathy scores and cognitive variables. Conclusions: PD patients show a stage dependent empathy score decrease which is driven mainly by cognitive aspects of empathy. However, emotional empathy aspects are not reduced.