In this study, we analyzed the extent to which certain clinical features contributed to quality of life (QoL) as measured by two different metrics in Parkinson's disease (PD) patients of high socioeconomic backgrounds.

PD is a neurodegenerative disease with motor and non-motor manifestations that have been previously reported to affect patient QoL.

Participants consisted of 124 patients with PD who were being followed by a movement disorders specialist at a university clinic. The Unified Parkinson Disease Rating Scale motor score (Part III) was used to determine disease severity. Clinicians completed the Quick Inventory of Depressive Symptoms - Clinician Rated (QIDS-C₁₆), and participants completed the Parkinson’s Disease Questionnaire-39 (PDQ-39) and EuroQoL (EQ-5D).

The majority of our participants were male (71.77%), white (89.52%), college-educated (66.13%), and in professional industry (73.39%). Motor symptoms of PD (bradykinesia and rigidity) as well as overall depression and specific depressive symptoms (anhedonia, somatic symptoms, concentration difficulties, appetite disturbance, sleep impairment) were all significantly correlated with QoL scores on both the PDQ-39 and EQ-5D surveys. Total depressive symptom severity (QIDS-C₁₆ total score) exhibited the strongest correlation with QoL scores. Of the specific depressive and motor symptoms, anhedonia and rigidity contributed the most to QoL. Tremor scores did not significantly correlate with QoL. Disease duration was significantly correlated with QoL for participants with Parkinson’s according to one QoL metric but not the other. 

Parkinson’s patients with high socioeconomic status are at risk for having diminished QoL due to both depressive and motor symptoms. While severity of motor symptoms certainly impacted QoL in our cohort, our findings suggest that depressive symptoms contribute more to impaired QoL than severe motor symptoms do. This phenomenon suggests that concomitant depression in PD as well as one’s psychological adjustment to disability may have a greater impact on QoL than disability itself.