The rate of bipolar disorder diagnosis among youth decreased between 2004 and 2010 compared with the prior 8 year period. The current study builds on a 2007 report that found an increasing rate of bipolar disorder diagnosis among youth between 1996 and 2004. Those findings caused many individuals to believe doctors were over diagnosing bipolar disorder, the researchers state. The follow-up study, published in Bipolar Disorders, explores whether rates were still climbing or declining after 2004.
The researchers used de-identified nationally representative data from the National Hospital Discharge Survey (NHDS) conducted annually by the National Center for Health Statistics. Looking at all diagnoses between 1996 and 2010, the researchers found 6.98% of all inpatient hospitalizations for individuals aged 5 and older were associated with a primary psychiatric diagnosis. Psychiatric hospitalizations increased from 6.76% in 1996 to 7.09% in 2004 to 6.35% in 2010.
Looking at adolescents, the number of psychiatric hospitalizations increased from 18.97% of all adolescent hospitalizations in 2004 to 22.04% in 2010.
Diagnosis of bipolar disorder among teens increased between 2004 and 2010 but decreased among children. The researchers attribute this change to changes in the rate of BD NOS/Cyclothymia diagnosis. Population adjusted rate of bipolar disorder diagnosis declined among adolescents between 2004 and 2010 compared with the previous time period. The researchers attribute the change in diagnosis to a scientific consensus around a diagnostic phenotype for bipolar disorder that occurred around 2004.
The researchers also explored common bipolar disorder symptoms, including depression. Their findings indicated “the population adjusted rate of diagnosis of depressive disorders among adolescents in the United States initially increased until the mid-2000s and then decreased until 2010. However, diagnosis of depressive disorders in US children increased between the mid-2000s and 2010, while the rate of diagnosis of depressive disorders in adults decreased,” they state.
Although the researchers made conclusions about the reason for the changes in diagnosis rates, the data do not identify the precise reasons. The study data also derive from billing claims, which means some individuals may have multiple admissions. The data also did not include secondary diagnoses, only primary.
While changes in diagnostic conditions may have influenced results, “further research is necessary to evaluate continuously changing diagnostic rates and to determine the exact causes of changing trends in diagnosis across time.”
Sherwood SN, Carlson GA, Freeman AJ. Decreasing rate of inpatient pediatric bipolar disorder diagnosis in the US between 2004 and 2010. Bipolar Disord. Published online October 18, 2021. doi:10.1111/bdi.13145