Longitudinal Mediating Effect of Depression on the Relationship between Excessive Daytime Sleepiness and Activities of Daily Living in Parkinson’s Disease

ABSTRACT

Objectives

Whether depression affects activities of daily living (ADLs) in patients with Parkinson’s disease (PD) via excessive daytime sleepiness (EDS) remains unclear; moreover, few longitudinal studies have been conducted.

Methods

We recruited 421 patients from the Parkinson’s Progression Markers Initiative. We constructed a latent growth mediation model to explore the longitudinal mediating effect of depression on the relationship between EDS and ADLs.

Results

EDS (p < .001) and depression scores (p < .001) both increased, and ADL scores (p < .001) decreased. Moreover, EDS was positively correlated with depression, whereas an increase in EDS significantly reduced ADLs. The initial value (95% confidence interval [CI]: 0.026, 0.154) and the rate of change (95% CI: 0.138, 0.514) of self-reported depression measured using the Geriatric Depression Scale(GDS) partially mediated the association between EDS and ADL score.

Conclusions

The indirect effect of the longitudinal changes of depression on the relationship between EDS and ADLs highlights the importance of depression changes in PD patients with EDS.

Clinical Implications

Depression should be considered a mediator by clinicians; preventing the worsening of depression is essential for improving ADLs in patients with PD, especially those with EDS.

KEYWORDS:

• Parkinson’s disease
• longitudinal mediation
• activities of daily living
• depression
• excessive daytime sleepiness

Clinical implications

●The significant association between depression and ADLs in people with PD highlights the importance of preventing depression.

●The non-significant correlation between the progression of depression and baseline depression symptoms suggests that it is essential to note changes in depression during the disease course, especially in PD patients without depression at baseline who exhibit changes in mood and EDS.

●The mediating effect of depression on the association between EDS and ADLs may be valuable for developing interventions to help patients with EDS improve their basic abilities.

Acknowledgments

All authors are grateful to the participants for their support and cooperation in making this research possible. We also thank the reviewers for their constructive ideas, and Sarina Iwabuchi, PhD, from Liwen Bianji (Edanz) (www.liwenbianji.cn) for editing the language of a draft of this manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

These data were derived from the following resources available in the public domain:[Parkinson’s Progression Markers Initiative (PPMI), URLs: www.ppmi-info.org]

Additional information

Funding

This work was supported by the National Natural Science Foundation of China (Grant number 81973154), and Graduate Innovation Project of ShanXi Province(Grant number 2021-14);Shanxi Postgraduate Innovation Project [2021Y367]