Restrictive and Binge-Purge OSFED Variants: Clinical Features and Comparisons With Classical Eating Disorders.

Objective: Current diagnostic nomenclature includes "atypical" eating disorders (EDs) under the term other specified feeding or eating disorder (OSFED). Previous studies suggest that individuals with OSFED have similar psychological and concurrent symptoms to individuals with "classical" EDs. Our study compared people with OSFED to those with classical EDs on indices reflecting ED pathology, concurrent psychological symptoms, personality traits, functional impairment, illness duration, and pretreatment motivation. We also compared OSFED variants characterized solely by restrictive eating behaviors (OSFED-R) to variants in which binge-eating and/or purging symptoms predominated (OSFED-B/P).

Methods: Participants were 836 treatment-seeking adults (185 AN-Restricting type [AN-R], 165 AN Binge-eating/purging type [AN-B/P], 276 BN, 104 OSFED-R, and 106 OSFED-B/P) starting outpatient ED treatment. Data were analyzed with generalized linear models.

Results: Overall, findings in individuals with OSFED were comparable to those in people with a "classical" ED diagnosis on self-reported measures of concurrent psychological symptoms, personality traits, functional impairment, illness duration, and treatment motivation. However, relative to people with AN-R, individuals with OSFED-R reported higher levels of psychological ED symptoms (p < 0.001). The OSFED-B/P group had even more ED-related psychological symptoms than did the OSFED-R group (p = 0.02), but did not differ from the AN-B/P and BN groups on any of our indices.

Discussion: Findings extend previous research, underscoring the point that OSFED syndromes have serious clinical implications, comparable to those associated with full-threshold AN and BN. Results also highlight the relevance of examining heterogeneity within the OSFED category in function of a restrictive vs. binge/purge distinction.