(P-310) Hypnotic Drug Use and Underlying Diagnoses Among Adolescents in Norway

Background: Hypnotic drug use is increasing among adolescents in Scandinavia. Knowledge about underlying morbidity is limited.

Objectives: To explore underlying disorders among adolescent hypnotic drug users.

Methods: A cohort study with linked data from nationwide registries: prescription data from the Norwegian Prescription Database, and diagnosis data from the primary (Primary Health Care Database) and secondary care (Norwegian Patient Registry). The study population was adolescents 13–17 years in Norway from 2008 to 2018. Hypnotic drugs included were alimemazine and Hypnotics and sedatives (ATC group N05C), excluding midazolam. None of the drugs were available without a prescription. Sleep disorders were defined as P06 (ICPC-2) and G47/F51 (ICD-10). All diagnoses from secondary health care were studied on a chapter level. The annual prevalence of hypnotic drug use and sleep disorders was calculated. Incident use in 2017 was defined as a dispensed hypnotic drug in 2017, with no prior use the previous 730 days. The proportions of incident users who had been in contact with secondary health care and received any ICD-10 diagnosis during the time of the first dispensed hypnotic drug ±6 months, as well as during their childhood (0-12 years), were calculated.

Results: The prevalence of hypnotic drug use increased from 2008 to 2018 (13.2-29.2/1000). An increase in prevalence was also seen for sleep disorders in primary and secondary care, but at a much lower level; reaching 8.5 and 2.5/1000, respectively, in 2018. In 2017, 2519 girls (16.5/1000) and 1718 boys (10.7/1000) were incident users. Of these, 82% of the girls and 77% of the boys were referred to secondary care, but only 3.2% received a sleep disorder diagnosis. However, high proportions received psychiatric disorders; 51.8% of the girls and 46.2% of the boys. In girls “Neurotic stress-related disorders” (F40-48) were most frequent (27.4%), while “Behavioral and emotional disorders” (F90-98) were most common in boys (23.6%). Incident adolescent users also had more ICD-10 diagnoses during childhood compared to the general population; most profound for infections and psychiatric disorders which were recorded almost 5 and 3 times more frequently among incident hypnotic drug users.

Conclusions: Hypnotic drugs were mostly used without diagnoses of primary sleep disorders. Moreover, the adolescents using hypnotics had a large disease burden, both during childhood and adolescence. Around the time of the hypnotic drug use, the adolescents were mainly diagnosed with psychiatric disorders in secondary health care.