Exogenous melatonin as a treatment for secondary sleep disorders: A systematic review and meta-analysis

Front Neuroendocrinol. 2019 Jan;52:22-28. doi: 10.1016/j.yfrne.2018.06.004. Epub 2018 Jun 15.


Melatonin is a physiological indoleamine involved in circadian rhythm regulation and it is currently used for secondary sleep disorders supported by empirical evidence. A small amount of evidence and some controversial results have been obtained in some randomized controlled trials (RCT). The objective of this meta-analysis is to determine the efficacy of exogenous melatonin versus placebo in managing secondary sleep disorders. Literature retrieval of eligible RCT was performed in 5 databases (PubMed, Embase, Cochrane Library, ClinicalTrials.gov, and Web of Science). In total, 7 studies of 205 patients were included. Pooled data demonstrate that exogenous melatonin lowers sleep onset latency and increases total sleep time, whereas it has little if any effect on sleep efficiency. Although, the efficacy of melatonin still requires further confirmation, this meta-analysis clearly supports the use of melatonin as a management for patients with secondary sleep disorders.

Keywords: Melatonin; Meta-analysis; Secondary sleep disorders; Sleep efficiency; Sleep onset latency; Total sleep time.

Publication types

  • Meta-Analysis
  • Research Support, Non-U.S. Gov't
  • Systematic Review

MeSH terms

  • Central Nervous System Depressants / pharmacology*
  • Humans
  • Melatonin / pharmacology*
  • Sleep Stages / drug effects*
  • Sleep Wake Disorders / drug therapy*


  • Central Nervous System Depressants
  • Melatonin