Affectivity and Its Disorders draws on Martin Heidegger’s phenomenology of moods and his conception of Befindlichkeit in an effort to critique traditional psychological and behaviorist views of affectivity. On Heidegger’s account, moods are not fleeting or contingent aspects of experience but rather constitutive of what it means ‘to be’ human insofar as they serve as the mediating horizon or atmosphere that makes it possible for things to affectively matter to us. The primary aim of this chapter is to explore the ways in which psychopathologic experience disrupts and modifies the structure of Befindlichkeit and the mediating capacity of moods. This structural disruption is examined from the perspectives of embodiment, being-with-others, and temporality.