The efficacy and safety of exogenous melatonin for primary sleep disorders. A meta-analysis

J Gen Intern Med. 2005 Dec;20(12):1151-8. doi: 10.1111/j.1525-1497.2005.0243.x.

Abstract

Background: Exogenous melatonin has been increasingly used in the management of sleep disorders.

Purpose: To conduct a systematic review of the efficacy and safety of exogenous melatonin in the management of primary sleep disorders.

Data sources: A number of electronic databases were searched. We reviewed the bibliographies of included studies and relevant reviews and conducted hand-searching.

Study selection: Randomized controlled trials (RCTs) were eligible for the efficacy review, and controlled trials were eligible for the safety review.

Data extraction: One reviewer extracted data, while the other verified data extracted. The Random Effects Model was used to analyze data.

Data synthesis: Melatonin decreased sleep onset latency (weighted mean difference [WMD]: -11.7 minutes; 95% confidence interval [CI]: -18.2, -5.2)); it was decreased to a greater extent in people with delayed sleep phase syndrome (WMD: -38.8 minutes; 95% CI: -50.3, -27.3; n=2) compared with people with insomnia (WMD: -7.2 minutes; 95% CI: -12.0, -2.4; n=12). The former result appears to be clinically important. There was no evidence of adverse effects of melatonin.

Conclusions: There is evidence to suggest that melatonin is not effective in treating most primary sleep disorders with short-term use (4 weeks or less); however, additional large-scale RCTs are needed before firm conclusions can be drawn. There is some evidence to suggest that melatonin is effective in treating delayed sleep phase syndrome with short-term use. There is evidence to suggest that melatonin is safe with short-term use (3 months or less).

Publication types

  • Meta-Analysis
  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, P.H.S.
  • Systematic Review

MeSH terms

  • Humans
  • Hypnotics and Sedatives / therapeutic use*
  • Melatonin / therapeutic use*
  • Sleep Wake Disorders / drug therapy*
  • Treatment Outcome

Substances

  • Hypnotics and Sedatives
  • Melatonin