Association between Physical Activity, Depression Severity and Parkinson's Symptoms in Older Adults with Parkinson's disease: A Cross-Sectional Study.

Background: Depression significantly impacts Parkinson's disease (PD) motor function, non-motor symptoms, and quality of life. While physical activity (PA) is associated with improved PD symptoms, the relationship between depression severity, PA levels, and PD symptoms remains underexplored. This study examines the associations between depression severity, PA, and PD motor and non-motor symptoms using a large dataset from the Fox Insight study.

Methods: This cross-sectional study analyzed data from 3,445 individuals with PD completed the Geriatric Depression Scale-Short Form (GDS-S), the Physical Activity Scale for the Elderly (PASE), the Unified Parkinson's Disease Rating Scale Part 2 (UPDRS-2), and the Non-Motor Symptoms Questionnaire (NMSQ). Participants were categorized into four groups based on GDS-S scores: normal (0-4), mild (5-8), moderate (9-11), and severe (≥12). Kruskal-Wallis tests, Pearson correlations, and multiple linear regression analyses were conducted to assess associations between depression severity, PA, and PD symptoms.

Results: Higher depression severity was associated with worse motor (UPDRS-2; χ²=756.72, p<0.001) and non-motor (NMSQ; χ²=1072.13, p<0.001) symptoms and lower PA levels (PASE; χ²=396.24, p<0.001). Regression analysis showed that NMSQ (β=0.449, p<0.001), UPDRS-2 (β=0.212, p<0.001), and PASE (β=-0.171, p<0.001) significantly predicted depression severity.

Conclusion: Depression severity in PD is strongly linked to increased PD symptom. These findings highlight the importance of integrating PA interventions and mental health strategies into PD management to improve overall well-being.