Melatonin may reduce self-harm in youth, but sleep experts urge caution amid rise in use

Key takeaways:

• Melatonin decreased relative risks for self-harm in youth who initiated treatment between 6 and 18 years.
• The results conflict with a previous study that concluded “the exact opposite,” a sleep expert said.

A recent study found that melatonin may reduce the risk for self-harm in youth, but experts recommend conducting comprehensive sleep assessments before initiation.

Melatonin is the most commonly used medication for sleep disturbance in children and adolescents in Sweden, although first-line treatments are behavioral interventions to improve sleep routines, Sarah Bergen, PhD, an associate professor of medical epidemiology and biostatistics at the Karolinska Institutet in Sweden, and colleagues wrote in the Journal of Child Psychology and Psychiatry.

Previous research has established a link between sleep disorders and self-harm, so Bergen and colleagues hypothesized that melatonin could potentially decrease the risk for self-harm by improving sleep.

“There has been little research on this topic before, [so] we were not sure such an association would be found,” Bergen told Healio.

Reductions in self-harm

The researchers conducted a population-based cohort study of 25,575 Swedish youth, 58.2% of whom were boys. All patients had initiated melatonin between ages 6 and 18 years. The median age at initiation was 13 years for boys and 15 years for girls.

The researchers found that, compared with the last unmedicated month, melatonin use was associated with decreased relative risks for self-harm, with an incidence rate ratio (IRR) of 0.58 (95% CI, 0.46-0.73) in the month following melatonin initiation.

The reduction in self-harm was particularly evident among those with depression or anxiety, with girls demonstrating greater absolute risks than boys, according to Bergen and colleagues. Compared with the last unmedicated month, the IRR for self-harm in the month following melatonin initiation was 0.46 (95% CI, 0.27-0.76) among adolescent females with psychiatric disorders.

The researchers concluded that “although nonpharmacological treatments were not investigated and causality of the findings cannot be claimed, this study supports the hypothesis that improving youths’ sleep hygiene may be an important intervention to reduce self-harm in this pediatric population.”

Sleep expert discusses implications

Sleep experts recommend that parents discuss the potential benefits and risks with health care professionals before starting melatonin. Last year, the American Academy of Sleep Medicine (AASM) issued an advisory encouraging such discussions amid a 530% increase in melatonin ingestions among children in the United States from 2012 to 2021.

Bergen agreed with the AASM’s guidance to consult providers before melatonin initiation while highlighting the medication’s viability.

“For young people with sleep problems, melatonin is a good option. Since the risk of serious side effects, overdose, or dependence is small, melatonin use should be encouraged for anyone with the appropriate indications,” she said. “In particular, adolescent girls with anxiety or depression stand to benefit considerably from improved sleep through melatonin use.”

In regards to the study findings, David Kuhlmann, MD, FAASM, medical director of sleep medicine at Bothwell Regional Health Center in Missouri and an AASM board member, told Healio that “it is possible that the decreased risk of self-harm is the result of the melatonin itself.” However, he added that “the authors also acknowledge that it may be from the attention to the sleep disorder from parents and clinicians.”

“In fact, the study may not be generalizable to other populations in part because melatonin is a prescription in Sweden requiring evaluation by a medical provider,” Kuhlmann said.

Furthermore, other evidence has provided varied results. Kuhlman referenced one Danish study published last year in the Journal of Clinical Sleep Medicine, which examined associations between melatonin use and suicide behavior and concluded “the exact opposite of this study.”

“Their conclusion was that treatment with melatonin was associated with an increase in both suicides and suicide attempts,” he said. “It is not surprising that there is conflicting data as it is impossible to perform controlled studies and they must be retrospective.”

Kuhlman did agree with Bergen and colleagues’ conclusion that addressing youth sleep hygiene could serve as an effective intervention for pediatric self-harm.

“The take-home message from both these studies is that psychiatric comorbidities are very common in patients with sleep disorders,” Kuhlman said. “Rather than just prescribing melatonin to try and cover up the insomnia, health care providers should perform a comprehensive sleep assessment to ensure that they are addressing potential underlying causes of poor sleep, especially given the incidence of ADHD, anxiety and depression in this population. Nonpharmacological treatments may also lead to better outcomes.”

References:

• Høier NK, et al. J Clin Sleep Med. 2022;doi:10.5664/jcsm.10118.
• Leone M, et al. J Child Psychol Psychiatry. 2023;doi:10.1111/jcpp.13785.