Melatonin usage in children and young adults, a registry-based cohort study.

Sleep disorder is common in children and adolescents, particularly in those with attention deficit hyperactivity disorder (ADHD) or autism spectrum disorder (ASD). While non-pharmacological treatment is first line, occasionally an add-on of an oral drug is needed. The endogenous hormone melatonin is increasingly used for sleep disorders in children and adolescents. In this registry-based cohort study we follow dispensation of melatonin in young individuals, 0-25 years of age, in Stockholm, Sweden during 2016-2019. In all 9980 individuals, were dispensed melatonin in 2016 and followed for 3 years. Child psychiatrist was the most common prescribing specialty, 55% of all prescriptions. Only 20% had a recorded diagnosis of sleep disorder. The majority, 65% had a neuro psychiatric diagnose. Half of the individuals had at least 4 prescribed drugs dispensed during the follow-up. Almost half of our cohort were dispensed melatonin during the entire study period and doses and volumes of drug dispensed increased by 50 and 100%, respectively. Continuous medication was most common among children 6-12 years, where 7 out of 10 individuals were still adherent after three years. As long-term safety data is lacking, we find this concerning, and this illustrates the need of long-term follow-up of melatonin use in children and young individuals.