Child and Adolescent Psychiatry Unit, Department of Psychiatry and Medical Psychology, Clínica Universitaria, University of Navarra, Pamplona, Spain. csoutullo@unav.es
OBJECTIVE: There is considerable skepticism outside the US over the prevalence of pediatric bipolar disorder (BD). We wished to evaluate the epidemiology of BD in children and adolescents in non-US samples. METHOD: We reviewed studies on the prevalence of BD in children and adolescents in international samples. We also describe our sample of 27 children with BD at the University of Navarra. RESULTS: There are important and frequently overlooked differences in the definition of BD between the International Classification of Diseases 10th edition (ICD-10) and DSM-IV and methodological differences in epidemiological studies that may partially explain international differences in prevalence of pediatric BD. The prevalence of bipolar spectrum disorder in young adults in Switzerland is 11%. In Holland the 6-month prevalence of mania in adolescents was 1.9% and of hypomania 0.9%. Only 1.2% of hospitalized youth (