Objectives : The early onset of mood symptoms in bipolar disorder has been associated with poor outcomes in many studies. However, aspects of the clinical course of bipolar disorder in children and adolescents are controversial. The goal of this article is to review the clinical characteristics and longitudinal course of children and adolescents with bipolar disorders. Methods : Searches were conducted in MedLine, PsycINFO, KISS, and RISS using the terms phenomenology, clinical course, outcome, BPD, pediatric, children and adolescents. Twenty-one reports were selected : either original articles reporting symptoms and clinical characteristics of subjects (ages 5-18 years), or published articles in reviewed journals about bipolar disorder in children and adolescents. Results : Approximately 70% of subjects with bipolar disorder recovered from their index episode, and 50% had at least 1 syndromal recurrence, particularly depressive episodes. For 60% of the follow-up time, subjects had syndromal or subsyndromal symptoms with numerous changes in symptoms and shifts of polarity. Approximately 20% of BP-II subjects converted BP-I. Conclusion : Bipolar disorders in children and adolescents are characterized by episodic illness with subsyndromal and syndromal episodes with mainly depressive and mixed symptoms and rapid mood changes. Extensive follow-up time is needed to evaluate the continuity of bipolar disorder symptoms from childhood to adulthood.