Bipolar disorder in children and adolescents: diagnostic inpatient rates from 2000 to 2013 in Germany

Background: Despite growing consensus on nosology and epidemiology of bipolar disorder (BD) in minors, differences remain. We contribute to this discussion by measuring long-term trends in the inpatient discharge rates of BD in minors. Methods: Nationwide German inpatient discharge diagnoses of BD and other related psychiatric disorders were mapped between 2008 and 2013 using registry data from the German Federal Health Monitoring System. This was compared with previously published data, 2000-2007, to assess long-term trends in diagnosis of BD at discharge. Long-term trends (2000-2013) were also computed. Results: Discharge diagnosis of BD increased by 18% (2.02-2.46 per 100,000) in minors. There was a significant increase of 24.1% in adolescents 15-19 years old (6.56-8.14 per 100,000). BD, at discharge, as a proportion of all psychiatric disorders, increased from 0.26% in 2008 to 0.27% in 2013. When analysing long-term trends (2000-2013), the rates for BD increased significantly as did trends for all mental disorders, except for psychotic disorders, which fell by almost 14%. Between 2000 and 2013, the rate for depression in minors increased by 730%. Limitations: The dataset consisted of cross-sectional administrative data points with diagnoses based on clinical criteria. Conclusions: The rate of BD as a discharge diagnosis in German minors has increased significantly, consistently exceeding the general trend for a rise in rates for mental disorders. Overall, the rate of discharge diagnosis of BD from inpatient units in Germany remains a small proportion of all psychiatric diagnoses.