Melatonin may help children with attention-deficit/hyperactivity disorder get more sleep, but behavior benefits are negligible, said Kristiaan B. Van der Heijden, Ph.D., of the Epilepsy Center Kempenhaeghe, Heeze, the Netherlands, and colleagues.
Surprisingly, melatonin had no significant effect on behavior, cognitive improvement, or quality of life. “We expected such improvements because sleep problems and sleep deprivation in children were associated with behavioral disturbances,” they said (J. Am. Acad. Child Adolesc. Psychiatry 2007;46:233–41).
The findings did confirm that melatonin improves sleep. In the randomized, double-blind study, 105 children aged 6–12 years took daily doses of 3 mg or 6 mg of melatonin (depending on their weight) or a placebo for 4 weeks.
The children who received melatonin fell asleep an average of 27 minutes earlier than at baseline, and those who took placebo fell asleep an average of 11 minutes later.
In addition, total sleep time increased by an average of 20 minutes in the melatonin group, and decreased by an average of 14 minutes in the placebo group.
Five patients in the melatonin group reported adverse events, including headache, hyperactivity, dizziness, and abdominal pain, but none of these patients discontinued the medication or withdrew from the study, and none required treatment for the adverse reactions.
Melatonin should be prescribed only for persistent and severe cases of insomnia, given the lack of additional benefits and the lack of systematic studies of the long-term effects of consistent melatonin use, the investigators wrote.