Diagnostic Crossover and Outcome Predictors in Eating Disorders According to DSM-IV and DSM-V Proposed Criteria: A 6-Year Follow-Up Study.

OBJECTIVE: To evaluate in a 6-year follow-up study the course of a large clinical sample of patients with eating disorders (EDs) who were treated with individual cognitive behavior therapy. The diagnostic crossover, recovery, and relapses were assessed, applying both Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) and the DSM-V proposed criteria. Patients with EDs move in and out of illness states over time, display frequent relapses, show a relevant lifetime psychiatric comorbidity, and migrate between different diagnoses. METHOD: A total of 793 patients (including anorexia nervosa, bulimia nervosa, binge eating disorder, and EDs not otherwise specified) were evaluated on the first day of admission, at the end of treatment, 3 years after the end of treatment, and 3 years after the first follow-up. Clinical data were collected through a face-to-face interview; diagnosis was performed by means of the Structured Clinical Interview for DSM-IV and the Eating Disorder Examination Questionnaire was applied. RESULTS: A consistent rate of relapse and crossover between the different diagnoses over time was observed. Mood disorders comorbidity has been found to be an important determinant of diagnostic instability, whereas the severity of shape concern represented a relevant outcome modifier. Using the DSM-V proposed criteria, most patients of EDs not otherwise specified were reclassified, so that the large majority of ED patients seeking treatment would be included in full-blown diagnoses. CONCLUSIONS: Among EDs, there are different subgroups of patients displaying various courses and outcomes. The diagnostic instability involves the large majority of patients. An integration of categorical and dimensional approaches could improve the psychopathological investigation and the treatment choices.