(P-564) Melatonin Use Among Children, Adolescents, and Young Adults. a Danish Nationwide Drug Utilization Study

Background: The use of melatonin is increasing in the younger population. Detailed knowledge on treatment patterns and user characteristics is needed.

Objectives: To provide a detailed characterization of the use of melatonin in children, adolescents, and young adults in Denmark during 2012-2019.

Methods: Using the nationwide Danish health registers, we performed a drug utilization study describing melatonin users aged 0-24 years according to incidence, treatment duration, morbidity, and specialty of prescribers. Analyses were done overall and by calendar year, sex, age, and region of residence.

Results: We identified 43,652 first time melatonin users with a median age of 16 years. During the study period, the incidence increased from 2.4 to 3.9/1,000 person-years. Among incident users in 2019, 53% filled only a single prescription (early discontinuation). Overall, 22% used melatonin two years after initiation, however, with considerable variation between age groups (57% among 5-9-year-olds vs. 7% of 18-24-year-olds). Psychiatric morbidity was very common among incident melatonin users with 77% having either a psychiatric disorder diagnosis, a filled prescription for another psychotropic drug, or a contact to private practicing psychiatrist +/- 12 months of the first prescription. The most common markers of psychiatric morbidity were filling of a prescription for methylphenidate (ATC N06BA04), a diagnosis of hyperkinetic disorder (ICD10 F90), or reaction to severe stress/adjustment disorder (ICD10 F43). The primary prescribers of new treatment were general practitioner (48%), followed by hospital physicians (27%).

Conclusions: The use of melatonin in Denmark has increased over the last decade among children, adolescents, and young adults and a substantial proportion of users have concurrent psychiatric morbidity. Long-term melatonin use was common among the younger age groups and as consequences hereof is largely unknown this should be a focus of interest. With the close association between poor mental health and inadequate sleep, it is unknown if the level of use is justified, but this in-depth description of young users may prime hypotheses for future research in requisite and adequate use of melatonin.