In this chapter, we address the ways in which ineffective emotion regulation may contribute to depression and comorbid emotional disorders in youth by interfering with effective self-regulation, and how new transdiagnostic treatments, such as the Unified Protocol for the Treatment of Emotional Disorders in Adolescence (UP-A; Ehrenreich et al., 2008), target these failures of self-regulation directly and indirectly via the UP-A's focus on increasing adaptive emotion regulation. Deficits in emotion regulation and self-regulation in emotional disorders, and both observed and hypothesized changes in these processes over the course of treatment, are illustrated through a case scenario. We also discuss preliminary evidence for the efficacy of the UP-A and future directions for applying theories of emotion regulation and self-regulation to treatment development and refinement of the Unified Protocol models. (PsycINFO Database Record (c) 2015 APA, all rights reserved