Eating disorder psychopathology, psychiatric impairment, and symptom frequency of atypical anorexia nervosa versus anorexia nervosa: A systematic review and meta-analysis.

Objectives: Restrictive eating disorders (EDs) occur across the weight spectrum, but historically more focus has been given to anorexia nervosa (AN) than atypical anorexia nervosa (atypAN). AtypAN's relegation to a diagnosis in the "other specified feeding and eating disorder" (OSFED) category and paucity of research surrounding atypAN invariably implies a less clinically severe ED. However, a growing body of research has begun to question the assumption that atypAN is less severe than AN. The current review and meta-analysis aimed to provide a comprehensive review to compare atypAN and AN on measures of eating disorder psychopathology, impairment, and symptom frequency to test whether atypAN is truly less clinically severe than AN.

Methods: Twenty articles that reported on atypAN and AN for at least one of the variables of interest were retrieved from PsycInfo, PubMed, and ProQuest.

Results: For eating-disorder psychopathology, results indicated that differences were nonsignificant for most indicators; however, atypAN was associated with significantly higher shape concern, weight concern, drive for thinness, body dissatisfaction, and overall eating-disorder psychopathology than AN. Results indicated that atypAN and AN did not significantly differ on clinical impairment or the frequency of inappropriate compensatory behaviors, whereas there was a significantly higher frequency of objective binge episodes in AN (vs. atypAN).

Discussion: Overall, findings indicated that, in contrast to the current classification system, atypAN and AN were not clinically distinct. Results underscore the need for equal access to treatment and equal insurance coverage for restrictive EDs across the weight spectrum.

Public Significance: The current meta-analysis found that atypAN was associated with higher drive for thinness, body dissatisfaction, shape concern, weight concern, and overall eating-disorder psychopathology than AN; whereas AN was associated with higher frequency of objective binge eating. Individuals with AN and atypAN did not differ on psychiatric impairment, quality-of-life, or frequency of compensatory behaviors, highlighting the need for equal access to care for restrictive EDs across the weight spectrum.