The addition of disruptive mood dysregulation disorder (DMDD) to the fifth edition of the "Diagnostic and Statistical Manual of Mental Disorders" ("DSM-5") was a controversial decision in 2013 and one that continues to the present. Researchers have found that DMDD exhibits both poor interrater reliability and discriminant validity from other common childhood-onset disorders, most notably oppositional defiant disorder (ODD). Research also indicates that DMDD might be better conceptualized as a component of ODD, and consistent with such a conceptualization, experts have recommended that effective treatments for ODD be applied to youth who fit the diagnostic pattern of DMDD. The purpose of this article is to help readers understand the problematic diagnostic validity associated with DMDD and to present recommended treatment strategies for working with youth who fit this challenging symptom profile.