The chapter examines the conceptual foundations and clinical implications of two contrasting models of eating disorder psychopathology: the disease model and the psychological model underpinning enhanced cognitive behavioural therapy (CBT-E). The disease model views eating disorders beyond the patient’s control, often requiring external eating control of the parents in adolescents and prescriptive treatment for symptom control and medical stabilization. In contrast, the CBT-E psychological model conceptualizes eating disorders as maintained by specific and modifiable cognitive and behavioural processes, particularly the over-evaluation of shape, weight, and eating control. Drawing on the transdiagnostic theory that informs CBT-E, the chapter outlines how this model promotes a collaborative, individualized approach in which patients actively engage in understanding and addressing the mechanisms that maintain their disorder. Core maintenance factors, such as dietary restriction, rigid and extreme dietary rules, and binge eating, are explored alongside additional processes, including clinical perfectionism, core low self-esteem, marked interpersonal difficulties, and mood intolerance. The chapter highlights how CBT-E differs from prescriptive or externally controlled treatments by fostering insight, autonomy, and sustainable psychological change. It concludes by addressing the clinical advantages of a unified, theoretically coherent framework across multidisciplinary settings, arguing that consistency in treatment language and approach enhances both therapeutic engagement and long-term recovery.