Prolonged-release melatonin in patients with idiopathic REM sleep behavior disorder

Ann Clin Transl Neurol. 2019 Mar 7;6(4):716-722. doi: 10.1002/acn3.753. eCollection 2019 Apr.


Objective: We investigated the effects of prolonged-release melatonin (PRM) on idiopathic rapid eye movement (REM) sleep behavior disorder (iRBD).

Methods: In this 4-week, randomized, double-blind, placebo-controlled pilot study, 30 participants with polysomnography-confirmed iRBD were assigned to receive PRM 2 mg per day, PRM 6 mg per day, or placebo. Medication was administered orally 30 min before bedtime. Primary outcomes included scores from the Clinical Global Impression-Improvement (CGI-I) and the Korean version of the RBD questionnaire-Hong Kong (RBDQ-KR). The secondary outcomes included RBDQ-KR factor 1 and factor 2 subscores, the Pittsburgh Sleep Quality Index score, the Epworth Sleepiness Scale score, the Short Form Health Survey version 2 score, and the frequency of dream-enacting behaviors assessed using a sleep diary.

Results: After 4 weeks, there were no differences in the proportions of patients with a CGI-I score of much improved or very much improved among the study groups. In addition, RBDQ-KR scores and secondary outcomes were not improved in all groups at 4 weeks, and there were no differences between the groups.

Conclusion: Our findings suggest that PRM may not be effective in treating RBD-related symptoms within the dose range used in this study. Further studies using doses higher than 6 mg per day are warranted.

MeSH terms

  • Adult
  • Double-Blind Method
  • Female
  • Hong Kong
  • Humans
  • Male
  • Melatonin / administration & dosage*
  • Melatonin / therapeutic use*
  • Middle Aged
  • Pilot Projects
  • Polysomnography / methods
  • REM Sleep Behavior Disorder / complications
  • REM Sleep Behavior Disorder / drug therapy*
  • Sleep / drug effects*
  • Surveys and Questionnaires
  • Treatment Outcome


  • Melatonin

Grant support

This work was funded by National Research Foundation of Korea (NRF) grant ; Minister of Science, ICT and Future Planning, Republic of Korea grants NRF‐2014R1A2A2A04003858 and 2017M3C7A1029485.