This article, the last in a series of 5, presents a detailed case summary in which thematic mapping, a novel method of case conceptualization, was used to conceptualize an adult struggling with chronic depression. The case illustrates the process and therapeutic outcomes that resulted from the therapist's use of the 3‐stage thematic mapping model: theme identification, theme interpretation, and theme intervention. The article also demonstrates how the case formulation guided the therapist in selecting therapeutic techniques that matched to the client's goals, needs, and interpersonal style. Overall, this article aims to demonstrate how thematic mapping utilizes transtheoretical and transdiagnostic approaches to create a case formulation that is client‐centered, process‐oriented, and useful across a broad spectrum of training.