Bipolarity in children.
Childhood and adolescent bipolar disorder have been less studied than adult onset bipolar illness. However, case reports of mania in childhood can be found as early as the mid 19th century. Historically, several factors have made the accurate diagnosis of bipolar disorder in childhood difficult: clinical bias against the diagnosis of mania in children; low base rate of disorder; symptom overlap between bipolar disorder and other more prevalent childhood-onset psychiatric disorders; and developmental constraints and variability in clinical presentation. The epidemiology of juvenile-onset bipolar disorder remains an open topic for research. The disorder appears to increase in prevalence with advancing age until young adulthood. Reported phenomenology of bipolar disorder in children and adolescents indicates a highly variable presentation with a developmental trend towards increased resemblance to the adult phenotype with increasing age of onset. Diagnostic accuracy for the disorder is improved by adherence to diagnostic and statistical manual of mental disorders (DSM) criteria and may be aided by structured or semistructured diagnostic interviews. The course of bipolar disorder in children and adolescents has also received limited systematic study. However, research to date supports a clinical picture of a relapsing, recurrent illness with substantial morbidity. Systematic studies of pharmacologic treatments of acute mania in children and adolescents are limited in number and scope. Clinical justification for the use of acute antimanic treatments such as lithium and valproic acid is still based upon studies conducted in adults. There remains an immediate and significant need for additional research into all aspects of juvenile-onset bipolar disorder.