Effects of Melatonin on Sleep Quality in Patients With Rapid Eye Movement Sleep Behavior Disorder: A Systematic Review and Meta-Analysis on Randomized Controlled Trials Studies

Background and Objective Rapid eye movement (REM) sleep behavior disorder (RBD) is a sleep disorder characterized by REM sleep without atonia, resulting in physical movements that interrupt sleep quality. Melatonin has been suggested as an alternative therapy for patient intolerant to clonazepam. A systematic review and meta-analysis were conducted to evaluate the effectiveness of melatonin in improving sleep quality in RBD patients, analyzing sleep parameters both objectively with polysomnography (PSG) and subjectively with sleep questionnaires.Methods This systematic review and meta-analysis adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidelines and the Cochrane Handbook. A comprehensive search was performed across various databases (PubMed, Web of Science, Scopus, Taylor and Francis, ProQuest). Study quality was assessed using the Cochrane Risk of Bias 2.0 tool, and data were analyzed using R Studio.Results Statistically, the results of PSG analysis showed a significant improvement in the sleep of RBD patients receiving melatonin, characterized by a decrease in wakefulness after sleep onset (WASO) (mean difference [MD]=-11.17, 95% confidence interval [CI] [-13.35; -8.99], p<0.0001) and sleep onset latency (SOL) (MD=-7.05, 95% CI [-11.40; -2.69], p=0.0015), as well as an increase in time in REM sleep (MD=3.93, 95% CI [2.88; 4.99], p<0.00001). However, evaluation using sleep questionnaires overall did not show significant results (pooled MD=0.18, 95% CI [-0.65; 1.02], p=0.6681).Conclusions PSG analysis showed that melatonin effectively improved objective sleep quality in RBD patients. However, questionnaire-based evaluations revealed that melatonin was not particularly effective in treating a subjective sleep complaint.