The effect of melatonin on sleep quality and daytime sleepiness in Parkinson’s disease: A systematic review and meta-analysis of randomized placebo-controlled trials
Date
2025-07-01
Authors
Azzam Zrineh
Rami Akwan
Muhammad M. Elsharkawy
Bashar Douden
Wadi Sleibi
Mohamed Eldesouki
Journal Title
Journal ISSN
Volume Title
Publisher
Elsevier
Abstract
Background: Sleep disturbances are common in Parkinson’s disease (PD), significantly impacting quality of life.
Melatonin may help, but evidence regarding dosage, formulation, and treatment duration remains inconclusive.
Objective: To quantitatively analyze the effect of melatonin on sleep quality and daytime sleepiness in patients
with PD.
Methods: We comprehensively searched multiple databases up to February 2025, selecting relevant randomized
controlled trials (RCTs). RevMan software was used for analysis. Subgroup analyses included treatment duration
(4 weeks vs. 8–12 weeks), dose (≤4 mg vs. >4 mg), and formulation (immediate-release vs. prolonged-release).
Results: Five RCTs (206 patients) were included. Doses ≤4 mg showed no significant improvement in total
Pittsburgh Sleep Quality Index (PSQI) scores (MD = 1.26, 95 % CI: 2.72 to 0.20). Doses >4 mg demonstrated
a stronger effect (MD = 2.90, 95 % CI: 4.02 to 1.78). Short-term use (4 weeks) significantly improved PSQI
scores (MD = 2.43, 95 % CI: 3.98 to 0.88), whereas longer treatment (8–12 weeks) showed a non-significant
effect (MD = 1.24, 95 % CI: 3.15 to 0.67). Immediate-release formulations significantly improved PSQI scores
(MD = 2.20, 95 % CI: 3.32 to 1.08), while prolonged-release formulations showed no significant effect (MD
= 0.61, 95 % CI: 4.15 to 2.93). Melatonin modestly reduced excessive daytime sleepiness measured by the
Epworth Sleepiness Scale (ESS) (MD: 0.97, 95 % CI: 1.81, 0.14).
Conclusion: Melatonin may improve sleep quality and reduce daytime sleepiness in PD patients, particularly with
short-term use of immediate-release formulations