MELATONIN
Is melatonin safe for children?
Melatonin is a naturally occurring
hormone released by the pineal gland. Melatonin levels respond to an individual's
natural circadian rhythms by increasing late in the afternoon/early evening
and decreasing dramatically during the day. Light exposure, either natural
or artificial, causes extremely rapid destruction of the hormone.
Traditionally, it was believed that normal melatonin production decreased
during adolescence, but a recent study that measured urinary metabolites
of this hormone found that production remained virtually constant throughout
childhood and adolescence; the perceived decrease was the result of stable
levels in a larger body mass. In fact, production remains constant throughout
much of life.
While there is an enormous amount of information available, there are
few well-controlled studies that have examined the safety, appropriate
dosing including amounts and timing, for use in special populations such
as children. However, the few published studies that have looked at use
of melatonin in children have generally found the product to be safe,
though most have focused on use in children with neurodevelopmental disabilities.
One study of 20 children with developmental disabilities found that children
given melatonin fell asleep significantly more quickly, but did not experience
overall longer sleep durations or wake less frequently. A second slightly
larger study of 46 children with neurodevelopmental disorders found that
sleep improved in 34 of the children and none experienced side effects.
Only a very few studies have examined the use of this hormone in children
without disability. For example, a study of 40 elementary school children
without neurologic problems who were experiencing delayed sleep onset
found that over the duration of the 4-week study, melatonin was relatively
safe and significantly more effective than placebo in advancing sleep
onset and increasing sleep. Of note, tests that examined attention span
in these children found that, even in those whose sleep improved, measures
of attention did not change.
The National Sleep Foundation suggests that the product may be useful
for teenagers who experience delayed-sleep-phase syndrome, an inability
to fall asleep during the early nighttime hours that causes problems in
awakening the next morning. However, appropriate dosing and duration of
use in teenagers is not known.
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