Cheap melatonin pills before bed could help fight depression in children, a study suggests.
Researchers in Sweden followed 25,500 children ages six to 18 who took one pill every night for about six months.
The risk of self-harm incidents halved in the year after they started taking the pills compared to the year before.
Researchers suggested the drop may have been caused by participants getting more sleep, which has mood-boosting benefits. But the study was observational and failed to prove that the pills were definitely behind the lower self-harm rates.
Taking melatonin pills before bed may help fight depression in children, study suggests (Stock)
Melatonin is a hormone critical to the body’s sleep-wake cycle, with levels rising in the evening as the sun goes down, signaling it’s time for bed, and falling to near zero during the day.
Supplements of the hormone have been available over the counter in the US since the mid-1990s and are available at most pharmacies and health stores for about 12 cents a pill.
More than four million American adults now use the supplements regularly, estimates show, a fivefold increase from two decades ago.
This is despite some evidence suggesting that melatonin can cause cognitive problems when taken over a long period of time, although this has not been conclusively proven.
But in Sweden – where the research was conducted – melatonin supplements were not available over the counter until 2020.
For the study, researchers combed through the national database for children ages six to 18 who had been given melatonin.
Young people included in the study were born between 1989 and 2008.
Among them, ADHD was the most common condition, affecting 14,000 participants, followed by anxiety and depression, each about 5,500.
In the study, each child took a melatonin pill before going to bed for about six months.
Boys were on average 13 years old when they received the prescription, while girls were 15 years old.
It was most common to get the prescription in November and least common in July and August – or the summer holidays.
Researchers then tracked the number of recorded injuries in the group in the year before and the year after starting treatment.
Overall, they recorded a 12 percent drop in injuries.
There were 5,696 in the year before melatonin started compared to 5,011 after, suggesting that melatonin may have helped participants struggling with depression or other conditions, they said.
Poisonings, including from drugs and personal care products, saw the biggest drop, falling 21 percent from 778 to 615 events over the two years. This was driven by girls, among whom events fell by 23 percent. It was not clear whether these poisonings were intentional as this was not recorded.
They were followed by falls, which fell 15 percent, from 1,970 to 1,669, and physical injuries, which fell from 4,585 to 4,056.
Researchers also conducted a risk-of-injury analysis that showed that the risk of self-harming events — such as poisonings — was cut in half.
The scientists suggested that melatonin may have helped the participants by improving their mood.
Lack of sleep is known to increase levels of the stress hormone cortisol and disrupt restorative long-wave sleep, both of which cause one’s mood to turn negative.
It can also make a person more sensitive to pain, by increasing activity in brain regions involved in interpreting pain — such as the somatosensory cortex at the top of the brain — while decreasing it in areas that work to dampen pain perception — such as the striatum and insula in the middle of the organ.
Research also shows that a lack of sleep in people with ADHD can exacerbate symptoms such as impulsive behavior, inattention, and hyperactivity.
Dr. Sarah Bergen, a psychologist at the Karolinska Institutet who led the research, said: ‘Our findings support the hypothesis that sleep interventions can reduce self-harm in this population, especially in girls.
“This suggests that melatonin may be responsible for the reduced self-harm rates, but we cannot rule out the possibility that the use of other psychiatric drugs or psychotherapy may have influenced the findings.”