Pediatric-onset bipolar disorder: a neglected clinical and public health problem.

Bipolar disorder (BPD), probably the most prevalent psychotic disorder in adults, has been relatively neglected or controversial in children and adolescents over the past century. We reviewed the literature on early-onset BPD. Estimates of prevalence, particularly before puberty, are limited by historical biases against pediatric mood disorders and by formidable diagnostic complexity and comorbidity. Although clinical features of pediatric and adult BPD have similarities, pediatric cases probably cannot be defined solely by features characteristic of adult cases. Onset was before age 20 years in at least 25% of reported BPD cases, with some increase in this incidence over the past century. Pediatric BPD is familial more often than is adult-onset BPD, may be associated with a premorbid cyclothymic or hyperthymic temperament, and can be precipitated by antidepressant treatment. Pediatric BPD episodes frequently include irritability, dysphoria, or psychotic symptoms; they are commonly chronic and carry high risks of substance abuse and suicide. BPD is often recognized in adolescents, but the syndrome or its antecedents are almost certainly underrecognized and undertreated in children. Controlled studies of short- and long-term treatment, course, and outcome in this disorder remain strikingly limited, and the syndrome urgently requires increased clinical and scientific interest.