A recent Norwegian survey showed that melatonin use among children between ages 4 and 17 has increased annually from 2004 to 2012, and that children as young as 4 take the medication for several years.

Melatonin is used to help people fall asleep. But some studies have shown that the drug delays puberty in some animals and causes an increased ovulation rate in sheep, according to Science Nordic.

“The question is whether melatonin may affect puberty and reproduction in humans. This is especially important for children treated with the hormone over extended periods,” says Ingeborg Hartz. She is a researcher at Hedmark University College and the Norwegian Institute of Public Health (FHI). Her study is part of a Department of Pharmacoepidemiology project at FHI.

The survey showed that 8,000 prescriptions were dispensed to children ages 4-17 in 2012. This reflects an increase in use from 3 per 1,000 boys in 2004 to 11 per thousand in 2012. The increase for girls went from 1.5 to almost 8 per 1,000 during the same time period, Science Nordic notes.

“The youngest children were between 4 and 8 years old when they began using melatonin. This age group included the most long-term users, with around half of them on the medication for over three years. It seems that use is widespread among children who are about to enter puberty,” says Ingeborg Hartz, a researcher at Hedmark University College and the Norwegian Institute of Public Health (FHI).

Nine of ten long-term users from the study also had a psychiatric or neurological diagnosis, with the majority being ADHD diagnoses. Melatonin use must be viewed in light of these diagnoses, according to Hartz.

“If the pills help children sleep, some people may feel that it’s fine to use them even though we don’t know enough about the long-term effects. But prescribing melatonin for children comes with a clear responsibility,” she says.

Steinar Madsen, the medical director at The Norwegian Medicines Agency (NOMA), says NOMA is very interested in how melatonin interacts with ADHD medications.

“Sleep difficulties can be a side-effect of ADHD medication. For short periods, using these medicines shouldn’t pose a problem,” he says, “but we would like to see more follow-up studies of children who are on them for several years.”

Source: Science Nordic