DSM-5 eating disorders and other specified eating and feeding disorders: is there a meaningful differentiation?

In the DSM-5 diagnostic criteria for eating disorders, two main groups appear, threshold eating disorders (TED; anorexia nervosa, bulimia nervosa, and binge eating disorder), and other specified feeding and eating disorders (OSFED). In addition to calculating prevalence of these two groups, we examined the degree to which they could be differentiated in terms of impairment and risk factors.

Adolescent female twins (N = 699) were interviewed with the Eating Disorder Examination on three occasions spanning 12.70-19.84 years of age. Assessments also included self-report measures related to impairment and risk.

Prevalence of DSM-5 ED in this adolescent population was 10.4%; 5.4% for TED and 5% for OSFED. Impairment levels did not distinguish TED and OSFED groups at any wave. Examination of latent risk factors showed TED and OSFED groups to share a common genetic basis; however, largely nonoverlapping unique environmental influences contributed to the two groups. Specific risk factors commonly differentiated the no ED and TED groups, but not OSFED.

The findings suggest that TED and OSFED groups cannot be discriminated by prevalence or impairment or genetic risk factors. It is anticipated that OSFED will possess limited clinical utility for adolescents. Future research should examine clinical cases of these two groups in terms of meaningful differences, and a research focus should be maintained on both groups. Further examination of specific environmental risk factors that may attenuate the level of symptoms between the two groups may provide useful information for prevention efforts.