Objective: To evaluate melatonin’s efficacy in enhancing sleep and motor symptoms in Parkinson’s disease (PD) through an updated systematic review and meta-analysis.
Background: Sleep disturbances significantly affect the quality of life in PD patients. Melatonin is considered a crucial regulator of circadian rhythms, according to which, it has been examined for its therapeutic benefits, though the evidence remains uncertain. This updated meta-analysis provides a clear clinical perspective, presenting new insights into the impact of melatonin on sleep and motor function in PD patients.
Method: We searched on PubMed, Embase, and Cochrane Library. Selection criteria included RCTs examining the effects of melatonin in PD. Trials comparing melatonin to placebo were included in the meta-analysis, while those with active comparators were reviewed qualitatively. Outcomes assessed were Parkinson’s Disease Sleep Scale (POSI), UPDRS-III, and total UPDRS scale. A random-effects meta-analysis was conducted, with heterogeneity assessed using the I² statistic. Risk of bias was assessed using ROB2 tool.
Results: A total of seven RCTs (N=334) were included, with six (N=218) in the meta-analysis. Before performing a sensitivity analysis, melatonin showed a trend towards improving POSI scores (MD: -1.19 [-2.06, -0.32], p=0.002, I²=64%). After excluding (Gilat 2020), which was a source of heterogeneity, melatonin significantly enhanced sleep quality (MD: -2.20 [-2.87, -1.52], p<0.0001, I²=0%). No significant impact was observed on UPDRS-III scores (MD: 0.71 [-2.72, 4.14], p=0.69, I²=0%) and in total UPDRS score (MD: -3.27 [-19.6, 12.61], p=0.69, I²=63%). The systematic review included (Hadi, 2022), in which it compared melatonin with clonazepam and trazodone, suggesting that melatonin could be potentially a safer replacement, however, it shows inconsistent efficacy.
Conclusion: Melatonin significantly enhances sleep quality in PD, particularly after adjusting for heterogeneity, but does not appear to impact motor symptoms. The systematic review highlights melatonin’s potential as a safer alternative to other pharmacological agents, though its effectiveness varies. Larger, well-powered trials are necessary to further clarify its role in PD-related sleep disturbances.
Effects of exogenous melatonin on POSI score
Effects of exogenous melatonin on POSI score
UPDRS III
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To cite this abstract in AMA style:
M. Alghaniem, A. Abunamoos, F. Qtaishat, A. Rababah, M. Abu Hasna, Y. Aljazi, M. Mustafa, F. Alnajjar, T. Patel, N. Hamam. Effects of Exogenous Melatonin on Sleep and Motor Symptoms in Parkinson’s Disease: A Systematic Review and Meta-Analysis [abstract]. Mov Disord. 2025; 40 (suppl 1). https://www.mdsabstracts.org/abstract/effects-of-exogenous-melatonin-on-sleep-and-motor-symptoms-in-parkinsons-disease-a-systematic-review-and-meta-analysis/. Accessed October 5, 2025.« Back to 2025 International Congress
MDS Abstracts - https://www.mdsabstracts.org/abstract/effects-of-exogenous-melatonin-on-sleep-and-motor-symptoms-in-parkinsons-disease-a-systematic-review-and-meta-analysis/