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

BMJ 2006; 332 doi: https://doi.org/10.1136/bmj.38731.532766.F6 (Published 16 February 2006) Cite this as: BMJ 2006;332:385

Rapid Response:

Elucidation, not noise – melatonin is effective for certain sleep disorders

Editor - The Buscemi and colleagues meta-analysis (1) concludes that
there is no evidence that melatonin is effective in treating secondary
sleep disorders or sleep disorders accompanying sleep restriction. Here,
readers need to recall that there is another meta-analysis by these
colleagues, pointing at the efficacy and safety of melatonin in the
management of chronic or primary insomnia (2). Sleep onset latency was
reduced on average by 16.5 min with benzodiazepines, 18.1 min with non-
benzodiazepines and 8.3 min with melatonin. Wakefulness after sleep onset
was reduced on average by 23.1, 12.6 and 9.7 min respectively. All these
were of statistical significance, except the last one, and may have
relevance to clinical practice.

A meta-analysis may contain errors, thereby increasing noise instead
of providing elucidation. The quality of information makes the difference.
This particular meta-analysis did have limitations in its methods. For
example, insomnia was considered to be secondary to a range of disorders
from developmental disability to chronic whiplash syndrome, induced
insomnia was considered as a medical condition in healthy volunteers, etc.

Treatment of insomnia needs to be based on the identification of its
cause. It is not surprising that melatonin is not effective for the
treatment of secondary insomnia. A key to the treatment is then the
principal disorder. Melatonin may or may not be of help. However, it is
effective for primary insomnia and jet lag as pointed out earlier in
responses to the meta-analysis in question.

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: 385-393.

2. Buscemi N, Vandermeer B, Friesen C, Bialy L, Tubman M, Ospina M,
et al. Manifestations and management of chronic insomnia in adults.
Evidence report/Technology assessment No. 125 (prepared by the University
of Alberta Evidence-based Practice Center, under Contract No. C400000021).
AHRQ Publication No. 05-E021-2. Rockville, Md: Agency for Healthcare
Research and Quality, June 2005.

Timo Partonen, MD, National Public Health Institute, Helsinki,
Finland

Outi Saarenpää-Heikkilä, MD, Tampere University Hospital, Tampere,
Finland

Markku Partinen, MD, Skogby Sleep Disorders Centre, Espoo, Finland

Competing interests:
None declared

Competing interests: No competing interests

03 May 2006
Timo Partonen
academy research fellow
Outi Saarenpää-Heikkilä, and Markku Partinen
National Public Health Institute, Mannerheimintie 166, FI-00300 Helsinki, Finland