Bipolar disorder (BD) is a chronic, recurrent disorder carrying high morbidity and mortality, leading to health costs of at least $45 billion per year (Kleinman et al., 2003). It is the sixth leading cause of disability among all illnesses (Murray & Lopez, 1996). Between 15 and 28% of bipolar adults experience illness onset before the age of 13, and between 50 and 66% of them experience it before the age of 19 (Leverich et al., 2002, 2003; Perlis et al., 2004). The exact prevalence in children is unknown, but an estimated 420,000-2,072,000 US children have the illness (Post & Kowatch, 2006). Persons with onset of BD in childhood or adolescence have a more severe, adverse, and continuously cycling course of illness than adults, often with a preponderance of mixed episodes, psychosis, suicidal ideation or behaviors, and multiple comorbidities (Geller et al., 2002). Without early intervention, early-onset BD patients can be derailed, sometimes irrevocably, in social, neurobiological, cognitive, and emotional development (Miklowitz et al., 2004).