Abstract
Does bipolar disorder exist in children? How common is childhood-onset bipolar disorder among adults? Are bipolar spectrum conditions relevant? Answers to these questions are key drivers of the design and interpretation of epidemiologic studies of pediatric bipolar disorder. In our commentary, we assert that Parry and colleagues have selectively attended to certain findings that support their thesis, while ignoring contradictory findings, and that they have assigned excessive meaning to relatively pedestrian methodologic limitations. Their singling out of the United States is done with criticism but without critical appraisal. We highlight the flawed logic and inferential leaps that sustain Parry et al's criticism despite contradictory information dating back over a century.