BMJ  2006;332:550 (4 March), doi:10.1136/bmj.332.7540.550

Letter

Does melatonin improve sleep?

Efficacy of melatonin

EDITOR—Buscemi et al in their meta-analysis report that melatonin is ineffective in treating secondary sleep disorders or sleep disorders accompanying sleep restriction such as jet lag or shift work.¹ The published reports in this domain certainly show some inconsistency, and now there is inconsistency in the meta-analyses.² Numerous published studies, mostly with a positive result, have not been included, even the first controlled jet lag trial, published in the BMJ.³

Buscemi et al may have done a disservice to people who do benefit from melatonin and may in consequence be denied access (in the United Kingdom) to this prescription-only medication. For example, the authors do not mention the importance of melatonin in blind sleep disorder and delayed sleep phase syndrome. Some of the data have appeared previously in a report from the Agency for Healthcare Research and Quality,³ where benefits for delayed sleep phase syndrome were identified.⁴

View larger version (41K): [in this window] [in a new window]

 

Successful use of melatonin to counter the effects of a change in time zones or shift work requires correct timing of treatment relative to internal circadian rhythms. Incorrect timing can lead to undesirable effects. It is difficult to time melatonin correctly in field studies. Uncontrolled exposure to natural light (which shifts internal timing), individual differences, and unscheduled sleep times all contribute to the problems. If a reliable and rapid method for assessing the timing of the human internal clock (and hence the timing of treatment) were available no doubt the efficacy of melatonin would be enhanced.

A more helpful approach to assessing the usefulness of melatonin would be to evaluate those few studies where circadian timing was either measured or accurately predicted before treatment.

Centre for Chronobiology, School of Biomedical and Molecular Sciences, University of Surrey, Guildford, Surrey GU2 7XH Arendtjo{at}aol.com

---

Competing interests: JA is a member of the sleep advisory board, Alliance Pharmaceuticals.

References

1. Buscemi N, Vandermeer B, Hooton N, Pandya R, Tjosvold L, Hartling L, et al. Efficacy and safety of exogenous melatonin for secondary sleep disorders and sleep disorders accompanying sleep restriction: meta-analysis. BMJ 2006;332: 385-93. (18 February.)[Abstract/Free Full Text]
2. Brzezinski A, Vangel MG, Wurtman RJ, Norrie G, Zhdanova I, Ben-Shushan A, Ford I. Effects of exogenous melatonin on sleep: a meta-analysis. Sleep Med Rev 2005;9: 41-50.[CrossRef][ISI][Medline]
3. Arendt J, Aldhous M, Marks V. Alleviation of jet-lag by melatonin: preliminary results of controlled double-blind trial. BMJ 1986;292: 1170.[ISI][Medline]
4. Agency for Healthcare Research and Quality. AHRQ issues new report on the safety and effectiveness of melatonin supplements. Press release, 8 December 2004. AHRQ. Rockville, MD, USA. www.ahrq.gov/news/press/pr2004/melatnpr.htm

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

Relevant Article

Efficacy and safety of exogenous melatonin for secondary sleep disorders and sleep disorders accompanying sleep restriction: meta-analysis

Nina Buscemi, Ben Vandermeer, Nicola Hooton, Rena Pandya, Lisa Tjosvold, Lisa Hartling, Sunita Vohra, Terry P Klassen, and Glen Baker
BMJ 2006 332: 385-393. [Abstract] [Full Text] [PDF]

This article has been cited by other articles:

• Koh, G. C.-H. MD MMed, Khoo, H. E. PhD, Wong, M. L. MD MPH, Koh, D. MD PhD (2008). The effects of problem-based learning during medical school on physician competency: a systematic review. CMAJ 178: 34-41 [Abstract] [Full text]