Incident Substance Use Disorder Following Anxiety Disorder in Privately Insured Youth

Purpose: Anxiety disorders in childhoodmight be associated with an increased risk of substance use disorders. Incident substance useerelated diagnoses were quantified in the 2 years after youth were newly diagnosed with an anxiety disorder and in a similar cohort of youthwithout diagnosed anxiety. Methods: Privately insured youth (10-17 years) were identified in a commercial claims database who were newly diagnosed with an anxiety disorder (2005-2014), treatment naive, and without baseline substance-related disorder diagnoses. The comparison cohort included age, sex, region, and date matched youth with equivalent baseline exclusions. We used KaplaneMeier estimator to calculate 2-year cumulative incidence of substance use disorder diagnosis following a new officebased anxiety disorder diagnosis (or match date for comparison cohort). Results: In 131,271 youth with a new anxiety disorder diagnosis (male = 41%, median age = 14 years), 1.5% (95% confidence interval = 1.5-1.6) had an incident substance use disorder diagnosis 1 year after their anxiety diagnosis, 2.9% (95% confidence interval = 2.8-3.0) by 2 years. Over the same period,.5% and 1.1% of the comparison cohort had incident substance use disorder diagnoses (n = 1,321,701). In the anxiety cohort, 2-ear incidence was higher in youth aged 14-17 years (4.6%) versus 10-13 years (.7%). Incidence of substance use diagnosis varied by anxiety disorder (e.g., 2-year incidence: 4.3% for post-traumatic stress disorder, 3.0% for generalized anxiety disorder). Conclusion: Approximately 3% of youth newly diagnosed with anxiety received an incident substance use disorder diagnosis within 2 years, almost threefold the incidence in youth without an anxiety diagnosis, emphasizing the need for increased awareness and prevention of substancerelated disorders in pediatric anxiety. (C) 2019 Society for Adolescent Health and Medicine. All rights reserved.