This document discusses differentiating between attention-deficit/hyperactivity disorder (ADHD) and bipolar disorder in children. It poses four key questions about whether they are separate illnesses, overlapping syndromes, coexistent symptoms, or if ADHD is a warning sign of bipolar disorder. It then provides background on the history and diagnostic criteria of ADHD, as well as statistics on its prevalence. It also discusses the challenges of diagnosing pediatric bipolar disorder and lists common developmental manifestations of manic symptoms in children. The document notes that ADHD and bipolar disorder are highly comorbid conditions and explores some ways to differentiate between the two.