The evolution of multirepresentational cognitive theorizing in psychopathology is illustrated by detailed discussion and analysis of a number of prototypical models of posttraumatic stress disorder (PTSD). Network and schema theories, which focus on a single, explicit aspect/format of mental representation, are compared with theories that focus on 2 or more explicit representational elements. The author argues that the latter theories provide a more complete account of PTSD data, though are not without their problems. Specifically, it is proposed that at least 3 separate representational elements-associative networks, verbal/propositional representations, and schemas-are required to generate a comprehensive cognitive theory of PTSD. The argument that the development of multirepresentational cognitive theory in PTSD is a paradigm case for the development of similar theories in other forms of psychopathology is elaborated, and a brief agenda is proposed promoting 2 levels of theorizing-deep, formal theory alongside more localized, applied theory.