Transdiagnostic vs. disorder-focused perspective in children and adolescents with eating disorders: Findings from a large multisite exploratory study

Background: The transdiagnostic model of eating disorders (ED) proposes common cognitive mechanisms in patients with ED psychopathology. Little is known about their role in the maintenance of ED in children and adolescents. This study aimed to determine whether the relationships between key factors (low self-esteem, weight and shape control, clinical perfectionism, interpersonal problems, distress and mood instability) and core maintaining mechanisms (binge-eating and restraint) would support a transdiagnostic theory in young patients. Methods: A total of 419 patients (mean age 14.7 ± 2.14 years; age range: 7-18 years; males 13.8%) diagnosed with an ED were assessed in six Italian clinical centers in 2013. Multiple comparisons between ED diagnosis, correlation analysis and principal component analysis (PCA) were performed. Results: Of the entire collective, 51.5% of patients were diagnosed with Anorexia Nervosa (AN), 12.3% were diagnosed with Bulimia Nervosa (BN) and 36.2% with Eating Disorder Not Otherwise Specified (EDNOS). In PCA, the core ED mechanisms, dietary restraint and binge eating, acted as poles of attraction of the other variables. The AN group was particularly linked to restraint and the BN group was particularly related to "Bulimia". Considering the diagnostic subtypes, there were no significant differences between the anorexic binge-purging group, bulimic purging group and bulimic non-purging group, which constituted a unique cluster related to affective, interpersonal problems and to perfectionism, indicating a very homogeneous subgroup. Restricting anorexic group (AN-R), related to shape concern and anxious-depressed mood, was not linked to the other subtypes. EDNOS appeared to be opposed to the AN-R group; the binge eating disorder group appeared to be independent from others. Conclusion: Our results suggest the presence of both specific and transdiagnostic mechanisms in ED subtypes, whose knowledge is of relevance for clinical practice.