Decreasing rate of inpatient pediatric bipolar disorder diagnosis between 2005 and 2015

Introduction: The rate of bipolar disorder (BD) diagnosis in youth increased between the mid-1990s and mid-2000s in the U.S. and remained low in other countries. The discrepancy resulted in concerns regarding misdiagnosis of BD. However, the longitudinal trajectory of BD diagnosis subsequent to the mid-2000s was unclear. Therefore, the current study assessed longitudinal changes in the rate of inpatient BD diagnosis in the state of Nevada between 2005 and 2015. Methods: Data included Medicaid administrative billing claims (n. = 48,108 unique admissions) for youth 5-17 hospitalized at one of five psychiatric inpatient hospitals in Nevada. Regressions assessed changes in the rate of diagnosis over time for BD and compared to depressive disorders (DD). Results: The rate of BD diagnosis declined between 2005 and 2015. The rate of DD diagnosis remained stable for boys and increased substantially for girls during the same time period. Limitations: Some individuals may have been repeatedly hospitalized throughout the study period and contribute more than one unique admission. Findings from this study were limited to a sample of Medicaid-insured youth in a single state. Conclusions: The rate of mood disorder diagnosis in inpatient units is changing. The use of BD as a diagnosis is decreasing in Nevada which may reflect US trends nationally, though still high by international comparison. In contrast, DD increased for girls but not boys. Awareness of the current diagnostic trends for BD may assist inpatient administrators and clinicians in preparing for anticipated service utilization and planning allocation of resources.