The aim of this study was to calculate time trends in incidence of diagnosed anxiety disorders, including obsessive-compulsive disorder, and post-traumatic stress disorder, and to examine changes in use of prescribed drugs in the Norwegian pediatric population. Furthermore, we aimed to investigate whether comorbid mental disorders are associated with the use of prescribed drugs. Nation-wide registries with data from 2008 to 2015 were used, covering diagnostic data from primary health care [the Norwegian database for the control and reimbursement of health expenses (KUHR)] and secondary health care [the Norwegian Patient registry (NPR)], and data on prescribed drugs [the Norwegian prescription database, (NorPD)]. Data from the two latter were linked. During the period 2010-2015, 19,154 children and adolescents (61% girls) received a first diagnosis of anxiety disorders in primary care. The corresponding number from secondary care was 17,115 (61% girls). The incidence of diagnosed anxiety disorders increased over time, especially in girls, with an overall raise of ~ 2 per 1000 children across 2010-2015. Anti-anxiety drugs were used by < 12% of diagnosed children and < 25% of diagnosed adolescents, mainly by those with several contacts with the specialist health care system. There was no strong indications of an increase over time. Of other drugs, the most frequently prescribed were hypnotics and psychostimulants. Psychiatric comorbidity (33-55%) contributed to the use of drugs, including anti-anxiety drugs. The incidence of diagnosed anxiety disorders increased from 2010 to 2015, but the percentage using anti-anxiety drugs was stable. Drug use appears to be in line with the Norwegian guidelines.
Keywords: Anxiety disorders; Comorbidity; Obsessive–compulsive disorder; Post-traumatic stress disorder; Prescription drugs.