Trends in diagnosis of bipolar and disruptive mood dysregulation disorders in children and youth

•The diagnosis of pediatric bipolar disorder rose substantially for 20 years before stabilizing around 2010. The increase in rates of bipolar disorder in children has been controversial and it remains unclear whether this trend represented an increase in recognition, an increase in incidence, or a broadening of the application of the diagnostic criteria. The diagnostic and statistical manual (DSM) of mental Disorders, fifth edition, may have attempted to clarify the diagnoses by creating the diagnosis of disruptive mood dysregulation disorder (DMDD) in 2013. DMDD is characterized by severe, recurrent temper outbursts and chronically irritable mood that should not be diagnosed before the age of 6 and with symptoms present for at least 12 months. The introduction of the diagnosis of DMDD may have an impact on the assignment of a bipolar diagnosis and mood disorder, not otherwise specified (NOS), in the pediatric population. There may also be a relationship between the use of other mood diagnoses and oppositional defiant disorder (ODD).•The current study aimed to assess the trends in the use of bipolar disorders and DMDD in a population of children and adolescents in Kentucky covered by Medicaid. Additionally, we wished to evaluate whether prior diagnoses of bipolar disorders, mood disorder (NOS), ADHD, or ODD predicted a diagnosis of DMDD following the implementation of DSM-5 diagnostic criteria.•The longitudinal nature of our data allowed for trends to be identified as DMDD was introduced. Over the years of our study, more children receiving Kentucky Medicaid were diagnosed with DMDD while rates of mood disorder NOS and bipolar disorder decreased. The demographic findings of our study suggest children diagnosed with DMDD are more likely to be older, black, male, and living in rural areas. : Rates of pediatric bipolar disorders have increased and some are concerned about diagnostic accuracy. Disruptive mood dysregulation disorder (DMDD) was added to the DSM-5 in 2013. The purpose of this study was to assess diagnostic trends of bipolar disorders and DMDD and to identify predictors of receiving the DMDD diagnosis since implementation of DSM-5. : Kentucky Medicaid claims from 2012–2017 for children under 18 years (N = 814,919; 2012 n = 473,389; 2013 n = 470,918; 2014 n = 499,094; 2015 n = 517,199; 2016 n = 529,048; 2017 n = 535,814) were used. Logistic regression was used to identify predictors of a diagnosis of DMDD in 2015–2017 for a sub-sample (n = 5,071).