Melatonin is a hormone that regulates sleep and wakefulness and is commonly used as a drug among children and young people with sleep disorders. A recent study by researchers from the Karolinska Institute in Stockholm examined whether melatonin treatment affects the self-injurious behaviour of children and young people, many of whom have a psychiatric diagnosis. The study found that the risk of self-harm increased prior to the prescription of melatonin and decreased after the initiation of treatment, particularly in girls. The study compared the same individuals before and after melatonin prescription and controlled for background factors that might affect the relationships. The researchers acknowledged that other treatments such as behavioural therapy could also have been used alongside melatonin, making it difficult to attribute the reduction in self-harming behaviour solely to melatonin. The study showed that even when antidepressants were removed from the analysis, melatonin appeared to have a positive effect. Overall, the researchers believe that better sleep is associated with better decision-making and overall wellbeing. In Sweden, the use of melatonin has increased significantly in recent years, with a corresponding increase in the prescription of sleeping pills and sedatives among young people.
Melatonin is a hormone that controls sleep and wakefulness. It is the most common drug among children and young people with sleep problems. In Sweden, use has increased sharply in recent years.
Since many of those who are prescribed melatonin have some form of psychiatric diagnosis, researchers from the Karolinska Institute in Stockholm wanted to find out if the treatment affects the self-injurious behavior of children and young people.
– Previous studies have looked at how other drugs, such as antidepressants, affect the risk of self-harm, but no one has examined the effect of melatonin in the same thorough way, says Sarah Bergen, researcher in medical epidemiology at the Karolinska Institute and the study’s lead author.
Big difference
A total of around 25,500 individuals between the ages of 6 and 18 who were prescribed melatonin were included. Of these, 87 percent had at least one psychiatric diagnosis such as ADHD, anxiety, or depression.
When the researchers compared the incidence of self-injurious behavior in the same individuals before and after they were prescribed melatonin, they saw a difference. The risk of self-harm increased prior to melatonin prescription and decreased months after initiation of treatment, particularly in girls. Because the individuals were compared to themselves, the researchers were able to control for background factors that might affect the relationships, such as genetics, the severity of sleep problems, or psychiatric diagnoses.
For example, the risk that girls would intentionally poison themselves was reduced by half in the first months after the melatonin treatment compared to the time before.
– We cannot say that it is the melatonin that reduces the risk of self-harming behaviour, it could be that the patients also received other treatment such as behavioral therapy that we are not aware of, but this points towards a connection, says Sarah Bergen.
Without antidepressants
Some of the study participants had also been prescribed antidepressants. But even when the researchers removed them from the analysis, the result remained. This points to the fact that melatonin could affect the risk in a positive way.
– It is simply the case that everyone makes better decisions if you sleep better. It’s about what you eat, how you perform at school and probably even whether you choose to hurt yourself or not, says Sarah Bergen.
Among the self-injurious behaviors that occurred, 57 percent involved some form of poisoning and 34 percent involved cuts. The data from the study comes from the years 2006 to 2013.
The study has been published in The Journal of Child Psychology and Psychiatry. Two of the researchers behind the study are employed by the pharmaceutical company Johnson & Johnson.
In 2011, sleeping pills and sedatives were prescribed to 16,102 young people aged 0 to 19 years. In 2021, the same figure was 83,768. Since 2020, melatonin can also be bought without a prescription at pharmacies.