Long-term stability of eating disorder diagnoses.

OBJECTIVE Data on the stability of eating disorder (ED) diagnoses (DSM-IV) over 12 years are presented for a large sample (N = 311) of female eating disordered patients with anorexia nervosa (AN), bulimia nervosa (BN), and binge eating disorder (BED). METHOD Assessments were made at the beginning of therapy and 2-, 6-, and 12-year follow-ups. Diagnoses were derived from the Structured Inventory for Anorexic and Bulimic Eating Disorders. Possible diagnostic outcome categories were AN, BN, BED, NOS, no ED, and deceased. RESULTS At all follow-ups, more patients changed from AN or BED to BN than vice versa. No diagnostic crossover from AN to BED or vice versa occurred. BED showed the greatest variability and AN had the greatest stability over time. While the long-term outcome of BN and BED is similar, AN had a considerably worse long-term outcome than either BN or BED. CONCLUSION Of the ED diagnoses, AN was most stable and BED most variable. The considerable diagnostic flux between BN and BED and similarities in course and outcome of BN and BED point to common biological and psychological maintaining processes. AN and BED are nosologically quite distant.