The Effectiveness of Melatonin for Sleep Disturbances in Parkinson' Disease: Systematic Review and Meta-Analysis
Abstract
Sleep disturbances in Parkinson's disease (PD) reduce quality of life. Melatonin, a sleep-wake hormone, shows treatment potential. However, its efficacy in PD remains unclear due to inconclusive findings across studies, warranting a systematic review to synthesise the available evidence. We searched PubMed, Cochrane, Web of Science, and Scopus for RCTs up to May 2025. Study quality was evaluated using the Cochrane Rob-2 tool. Statistical analysis was conducted using Review Manager version 5.4.1 with outcomes expressed as mean differences (MD) with 95% confidence intervals (CI). Out of eight studies with 409 PD patients, seven studies entered a meta-analysis that showed melatonin improved sleep quality and insomnia, as indicated by Pittsburgh Sleep Quality Index (PSQI) (MD = -1.75 [-2.94 to -0.55]; p = 0.004) and Epworth Sleepiness Scale (ESS) (MD = -1.07 [-1.87 to -0.27]; p = 0.009). Melatonin showed no significant impact on objective sleep parameters. However, sleep onset latency (MD = -9.74 [-17.47 to -2.02]; p = 0.001) and total sleep time (SMD = 0.84 [0.47 to 1.21]; p < 0.00001) improved, favouring melatonin, after adjusting for heterogeneity. Melatonin did not significantly change REM Sleep Behaviour Disorder Screening Questionnaire (RBDSQ) (MD = 0.71 [-0.44 to 1.86]; p = 0.23). No significant differences was found between melatonin and clonazepam in ESS (MD = -2.65 [-5.36 to 0.06]; p = 0.06). In conclusion, melatonin is a well-tolerated treatment that improves sleep…
How strong is the evidence?
Evidence Hub reads this as a meta-analysis, done in people. Its evidence level is 1 of 5 (Highest · pooled evidence). Pooled evidence from several studies sits at the top of the evidence pyramid. Reported size: 409 participants or records.
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