In elderly patients with PD, depressive mood directly impairs sleep quality and also exerts an indirect negative effect via fear related to physiological health deterioration.
Key Findings
Results
Sleep quality was significantly negatively correlated with depressive mood, total fear of progression, and physiological health fear in elderly Parkinson's disease patients.
Sample: 234 elderly patients with PD attending the Affiliated Hospital of Nantong University, enrolled between June 2024 and April 2025.
Sleep quality median (IQR): 104 (84–130) on the Parkinson's Disease Sleep Scale (PDSS); depressive mood median (IQR): 7 (3–11) on GDS-15.
Correlations with sleep quality: depressive mood r = -0.434, total FoP r = -0.318, physiological health fear r = -0.419 (all p < 0.01).
Social-family fear subscale also negatively correlated with sleep quality but more weakly (r = -0.168, p < 0.05).
Spearman's rank correlation analysis was used to assess associations among variables.
Results
Depressive mood was positively correlated with total fear of progression, physiological health fear, and social-family fear.
Correlation between depressive mood and total FoP: r = 0.632, p < 0.01.
Correlation between depressive mood and physiological health fear: r = 0.675, p < 0.01.
Correlation between depressive mood and social-family fear: r = 0.481, p < 0.01.
Physiological health fear showed the strongest correlation with depressive mood among the FoP subscales.
Assessed using the Fear of Progression Questionnaire Short Form (FoP-Q-SF); total FoP median (IQR): 35 (30–40); physiological health fear: 19 (17–22); social-family fear: 16 (14–18).
Results
Depressive mood had a significant direct effect on sleep quality in elderly Parkinson's disease patients.
Direct effect of depressive mood on sleep quality: β = -1.772, 95% CI: -2.839 to -0.706.
Mediation analyses were conducted using the PROCESS macro (version 4.0) in SPSS.
The confidence interval for the direct effect excluded zero, confirming statistical significance.
This direct effect was maintained even after accounting for the mediating role of physiological health fear.
Results
Physiological health fear partially mediated the relationship between depressive mood and sleep quality.
Indirect effect of depressive mood on sleep quality through physiological health fear: β = -1.010, 95% CI: -1.723 to -0.314.
The confidence interval for the indirect effect excluded zero, confirming significant mediation.
Mediation was partial, as the direct effect of depressive mood on sleep quality remained significant.
The social-family fear subscale of FoP was not identified as a significant mediator in the reported mediation analysis.
The pathway is: depressive mood → increased physiological health fear → impaired sleep quality.
Methods
The study used a cross-sectional design with standardized questionnaires administered to a single-center hospital sample of elderly PD patients.
234 elderly patients with PD were enrolled from the Affiliated Hospital of Nantong University between June 2024 and April 2025.
Instruments included the General Demographic Questionnaire, GDS-15 (depressive mood), FoP-Q-SF (fear of progression with physiological health and social-family subscales), and PDSS (sleep quality).
Cross-sectional design limits causal inference beyond the directional mediation model.
Single-center recruitment may limit generalizability of findings.
What This Means
This research suggests that in elderly people with Parkinson's disease, feeling depressed is linked to poorer sleep, and that this relationship works through two pathways. First, depression directly worsens sleep quality on its own. Second, depression appears to increase fears about physical health decline — such as worry about getting sicker or losing physical function — and these fears in turn further impair sleep. The study surveyed 234 Parkinson's disease patients in China, asking them about their mood, fears about the future, and sleep quality using validated questionnaires.
The study found that fear specifically related to physical health deterioration (called 'physiological health fear') was a meaningful link between depression and poor sleep, while fear about social and family impacts played a smaller role. Depression and physiological health fear were strongly correlated with each other, and both were associated with worse sleep scores on the Parkinson's Disease Sleep Scale.
This research suggests that addressing sleep problems in elderly Parkinson's disease patients may require attention to both depression and disease-related fears, particularly concerns about physical health decline, rather than focusing on sleep alone. Interventions targeting these psychological factors — such as therapies that reduce fear of disease progression alongside treatment for depression — could potentially lead to better sleep outcomes for this population.
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Wu L, Lu L, Zhang X, Xu T, Gu X, Shen C. (2026). The Mediating Effect of Physiological Health Fear Between Depressive Mood and Sleep Quality in Elderly Parkinson's Disease Patients.. Brain and behavior. https://doi.org/10.1002/brb3.71670