ORIGINAL ARTICLE Effectiveness of intensive cognitive behavioral therapy in adolescents and adults with anorexia nervosa Riccardo Dalle Grave | Maddalena Conti | Simona Calugi Department of Eating and Weight Disorders, Villa Garda Hospital, Garda (VR), Veneto, Italy Correspondence Riccardo Dalle Grave and Simona Calugi, Department of Eating and Weight Disorders, Villa Garda Hospital, Via Monte Baldo 89 37016 Garda (VR), Veneto, Italy. Email: rdalleg@gmail.com (R. D. G.) and si. calugi@gmail.com (S. C.) Action Editor: Tracey Wade Abstract Objective: This study aimed to compare the effectiveness of an intensive treatment based on enhanced cognitive behavioral therapy (CBT-E) in adolescent and adult patients with anorexia nervosa. Methods: A total of 150 consecutive patients (74 adolescents and 81 adults) were admitted to a 20-week intensive CBT-E program (13 weeks of inpatient followed by 7 weeks of day-hospital treatment). All patients had responded poorly to previous outpatient treatments and were assessed at admission, end of treatment (EOT), and 20- and 60-week follow-ups. Results: About 70% of eligible patients began the program, and more than 85% com- pleted it. Body mass index (BMI) in adults and BMI-for-age percentile in adolescents improved significantly from baseline to EOT, remained stable until 20-week follow- up, and slightly decreased from 20-week follow-up to 60-week follow-up, while remaining in the lower normal range. Eating disorder psychopathology, general psy- chopathology, and clinical impairment scores decreased significantly at EOT and showed only a slight increase from EOT to follow-ups. No difference was found between adolescent and adult patients in treatment acceptance, dropout, or any out- come measure. Discussion: These findings indicate that intensive CBT-E seems to be an effective treatment for severely ill adolescent and adult patients with anorexia nervosa. KEYWORDS anorexia nervosa, cognitive behavioral therapy, adults, adolescents, eating disorders, inpatient treatment 1 | INTRODUCTION Outpatient settings are ideal for the treatment of patients with anorexia nervosa. This is because outpatient treatment is less disrup- tive than inpatient, meaning that the changes made are more likely to last, as patients make them while living in their normal environment. However, as more than 50% of patients do not achieve remission, even with the most effective outpatient treatments (Byrne et al., 2017; Dalle Grave, Sartirana, & Calugi, 2019; Lock et al., 2010), and some cannot be managed safely on an outpatient basis, a more intensive treatment may become necessary. The need for intensive levels of care in adolescents is also justi- fied by the fact that they are particularly vulnerable to the effects of being underweight and undernourished, as their organs have not yet fully developed. Indeed, if weight regain does not occur through out- patient treatment within a reasonable timeframe, the prolonged per- sistence of malnutrition may be associated with severe, in some cases irreversible, physical impairment (e.g., osteoporosis, pubertal delay, and growth arrest) (Katzman, 2005); psychological regression and parental dependency (Crisp, 1997); social isolation and identity dam- age (Cooper & Stewart, 2008); and increased risk of death (Smink, van Hoeken, & Hoek, 2013). Received: 19 May 2020 Revised: 16 June 2020 Accepted: 16 June 2020 DOI: 10.1002/eat.23337 Int J Eat Disord. 2020;1–11. wileyonlinelibrary.com/journal/eat © 2020 Wiley Periodicals LLC 1