To the Editor: We appreciate Dr. Pincus’s comments on our article. We suggested these clinical phenotypes for juvenile mania because of the difficulties that arise when clinicians and researchers try to apply the DSM-IV criteria to children. The question of whether there is a fundamental distinction between these categories is an empirical one, and in the article, we suggested research strategies for addressing it (see our Table 1). For example, it is important to ascertain whether there are consistent differences between the phenotypes in neuropsychological and physiological function, longitudinal course, familial variables, etc. Should such differences exist, subsequent studies in adults would be warranted.