Melatonin improved sleep ratings in Parkinson's disease, with limited clinical significance
Trials in Parkinson's disease found improvements in sleep questionnaires, but sleep-quality changes fell short of a clinically meaningful threshold. Initial analyses showed no significant improvement in objectively measured sleep.
Based on the published abstract. The full paper may contain additional methods, results and limitations.
The 30-second takeaway
Melatonin improved questionnaire measures of sleep quality and daytime sleepiness in people with Parkinson's disease, but the sleep-quality improvements did not reach the threshold considered clinically important. Measured sleep outcomes were initially inconclusive. Some became favorable after accounting for differences between studies, so the overall evidence does not show consistent improvement across all sleep outcomes.
The abstract omits treatment durations and most comparator details. Changes in measured sleep depended on adjustments for differences between studies, while the authors explicitly limit the clinical significance of subjective sleep-quality improvements.
Statistical improvement versus noticeable change
A statistically significant questionnaire difference can still fall below the minimum change considered clinically important. The authors reported this distinction for subjective sleep quality, limiting what the favorable scores establish about the practical value of the improvement.
The less favorable results matter
A questionnaire screening for REM sleep behavior disorder did not improve significantly. Melatonin also did not differ significantly from clonazepam for daytime sleepiness. These findings leave effects uncertain rather than proving no effect or equivalence between treatments.
The original publication
The Effectiveness of Melatonin for Sleep Disturbances in Parkinson' Disease: Systematic Review and Meta-Analysis.
Yousef O, Abouelmagd ME, Khaddam H et al.
J Sleep Res · 2026
- PubMed ID
- 40588412
- Record checked
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