Metacognitive Interpersonal Therapy Across Transdiagnostic Eating Disorders, Including Underweight

The goal of this clinical trial is to assess if Metacognitive Interpersonal Therapy for Eating Disorders (MIT-ED) is effective for treating various forms of Eating Disorders (ED) and reducing dropout rates. The trial will also evaluate its feasibility and outcomes in a patient group including also underweight participants. The main questions it aims to answer are: * Does MIT-ED improve eating disorder symptoms and reduce overall maintenance factors, as alexithymia, emotional dysregulation, maladaptive perfectionism, and self-esteem? * Is MIT-ED effective in reducing the severity of personality disorders and associated global psychiatric symptoms? * What are the dropout rates and adherence levels for patients receiving MIT-ED? Participants will: * Undergo an initial screening to confirm eligibility, including a comprehensive clinical interview and assessments based on inclusion and exclusion criteria for the study. * Receive up to 40 individual sessions of MIT-ED, each lasting 50-60 minutes, over a period of approximately 10-12 months. * Attend regular assessment focusing on eating disorder symptoms (Eating Disorder Examination Questionnaire, EDE-Q 6.0, and ED Interview, EDE), emotional dysregulation (Difficulties in Emotion Regulation Scale, DERS), alexithymia (Toronto Alexithymia Scale-20, TAS-20), and self-esteem (Rosenberg Self-Esteem Scale, RSES). Assessment will be conducted at baseline (before starting MIT-ED sessions), after 20 MIT-ED sessions (approximately after 5 months), post-treatment (approximately after 10 months), and at 3 months follow-up. A longer 12-months follow-up is planned. Researchers will evaluate the effectiveness of MIT-ED based on treatment adherence, symptom improvement, and the reduction of maintenance mechanisms associated with Eating Disorders. Positive results could support the design of a larger, controlled Randomized Clinical Trial (RCT).