Impaired cognitive processing such as adverse decision-making is characteristic of major depressive disorder and can have considerable negative psychosocial consequences. This chapter presents and discusses existing theories and therapeutic approaches relevant to decision-making in depression. We show that, despite significant progress in fundamental research, there are still major gaps in our current understanding of adverse decision-making in major depressive disorder. Moreover, existing psychotherapeutic treatment approaches do not directly target adverse decision-making behaviors but do so inadvertently. Currently, only few treatment approaches (e.g., problem-solving and self-management skills) have been developed that primarily focus on treating adverse decision-making behavior. Therefore, a better understanding of altered decision-making processes in this clinical population is needed in order to better target adverse decision-making and associated problems, and to develop better therapeutic interventions.