Abstract
Objective: To examine the relationship between psychological stress and Parkinson’s disease progression.
Background: Animal studies suggest that Parkinson’s disease (PD) pathology is negatively affected by stress. More stressful life events may increase the risk of PD. Stress increases damage to dopamine cells and results in more severe parkinsonian symptoms in animal studies. In humans, acute stress can worsen bradykinesia, motor blocking (freezing), and tremor and it is hypothesized that stress may negatively affect dopamine synthesis and release.
Design/Methods: Data from the National Parkinson’s Foundation Quality Improvement Initiative (NPF-QII) was analyzed. The design, data collection, and approach to case-mix adjustment for the study has been described previously (Okun, 2011). All NPF-QII participants able to walk unassisted at baseline were included. A stress proxy score (derived from PDQ-39 and MCSI), a mobility proxy score (derived from iTUG and PDQ-39), and an overall health status score (derived from PDQ-39, falls score, hospital admissions, and cognitive score) were calculated for each subject (n=4,155). Excess stress was identified as positive deviation from the linear regression between the stress proxy score and a normalized combination of the other outcomes measured (motor, cognitive, falls, and other PDQ-39 domains). This “excess stress” (ES) score reflects the emotional stress above that typically resulting from disease severity or overall health.
Results: 1) The stress proxy score predicts mortality but the ES score does not (p<0.001). 2) high baseline stress proxy score predicts worsening mobility on follow-up (p<0.001; R2=0.026), and high ES also predicts worsening mobility (p=0.0014; R2=0.0025).
Conclusions: Stress may be a modifiable risk factor for disease progression.
Study Supported by: National Parkinson Foundation
Disclosure: Dr. Hiller has nothing to disclose. Dr. Quinn has received personal compensation for activities with Novartis as a speaker. Dr. Schmidt has nothing to disclose.
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