Transdiagnostic approaches have implications in the treatment of psychological disorders as a number of treatment protocols have been developed based on this perspective. Clark has distinguished three perspectives in transdiagnostic cognitive-behavioral therapy: a) The transdiagnostic practice, a pragmatic perspective that includes components of various disorder-specific intervention protocols whose aim is to determine which are the active components in samples with those disorders. The contributions of Norton, Andrews and Titov, and the study: Coordinated Anxiety Learning and Management (CALM) belong to this category. b) The transdiagnostic theory, that specifies a theoretical framework which outlines the common psychological constructs that influence the maintenance of ED. For instance, the tripartite model of anxiety and depression, with positive and negative affect as relevant constructs. c) The Unified Protocol. The Barlow's team has designed a protocol, adequate for the treatment of ED which focuses on four essential aspects: to increase present-focused emotional awareness, to identify and modify emotional avoidance patterns, to promote the cognitive flexibility and to facilitate exposure to avoided situations and sensations.