In their study on US trends in the outpatient diagnosis of bipolar disorder (BD), Moreno et al1 reported a nearly 40-fold increase of BD diagnoses from 1994 to 2003 in children and adolescents 19 years and younger. Increasing BD prevalence rates in youth are a matter of ongoing controversy in international child psychiatry. We would like to contribute to this discussion from a European perspective.
Using nationwide register data from the German Federal Health Monitoring System, we investigated inpatient diagnostic trends for 2000 to 2005. During this period, hospitalization rates for BD in youths 19 years and younger rose significantly from 1.13 to 1.78 per 100 000 people (χ2 = 145.69; P < .001; odds ratio, 1.58). Still,
this rise is far more moderate than the 40-fold increase in the United States, and the estimated underlying prevalence is much lower. Lower prevalence rates of BD in youth than in the United States have been reported from other European countries, including the United Kingdom,
Ireland, and Denmark,2 raising the question of how this transatlantic discrepancy might be explained.