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

Abstract

ObjectivesRestrictive 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.MethodsTwenty articles that reported on atypAN and AN for at least one of the variables of interest were retrieved from PsycInfo, PubMed, and ProQuest.ResultsFor 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).DiscussionOverall, 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 SignificanceThe 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.

An examination of adults with atypical anorexia nervosa at admission to treatment at higher levels of care: An attempt to increase diagnostic clarity

“…Endorsing these cognitive aspects of AN was also highly correlated with the severity of weight loss, but not the time frame of weight loss, highlighting the complexity and importance of further research to delineate these aspects of the operational definition of atypical AN. The high baseline average of these ED cognitions in our sample is consistent with other studies of patients with atypical AN (Johnson-Munguia et al, 2024). Inconsistent with previous research that has found associations between ED symptomatology and depressive disorders (Bodell et al, 2012;Brand-Gothelf et al, 2014) due to measurement-related variance in that predictors and outcomes come from the same self-report measure.…”

“…While this has decreased the prevalence of OSFED as desired (Lindvall Dahlgren et al, 2017;Machado et al, 2013), the natural taxonomic progression and increased awareness has resulted in increased prevalence of atypical AN and thus confusion around its operational definition (Masheb et al, 2021). The results of the current study are consistent with previous research in demonstrating the severity of ED cognitions and depressive symptomatology in atypical AN (e.g., Bachner-Melman et al, 2023;Johnson-Munguia et al, 2024), and the lack of association between a larger pretreatment weight loss (>10%) and Eating Concern, Restraint, or depressive symptoms (Forney et al, 2017). This study was novel in noting the lack of association between a shorter weight loss time frame (≤3 months) and Eating Concern, Restraint, or depressive symptoms.…”

“…Despite the implied recognition of including ED cognitions within the definition of atypical AN (all of the criteria for AN are met except…), the import of these cognitions has not been explicitly stated, nor have most researchers specified the ED cognitions included in their atypical AN populations; however, a recent meta-analysis found that atypical AN was associated with greater ED cognitions than AN (Johnson-Munguia et al, 2024). Birgegård et al (2023) have also noted the evidence that "disturbed views of weight and shape" are equally applicable to atypical AN as to AN (e.g., Lydecker et al, 2022;Mitchison et al, 2017;Sharpe et al, 2018).…”

Understanding community provider practices in diagnosing and treating atypical anorexia nervosa: A mixed methods study

“…AN and atypical AN are currently described as separate psychiatric disorders (American Psychiatric Association, 2022). However, recent meta-analyses found more similarities than differences between these two disorders (Johnson-Munguia et al, 2024;Walsh et al, 2022).…”

A case for re‐conceptualizing the ‘atypical’—A lived experience perspective

“…To a mind already sensitized to quantification and binaries, anorexia nervosa felt 'pure' and legitimized while atypical-alien, other (uncannily reflecting the diagnostic category it sits within). And our health systems convey this; the experiences of people with anorexia who are not 'clinically' underweight are often doubted, invalidated and nullified as they are 'not sick enough' (Barko & Moorman, 2023) when indeed, they are (Johnson-Munguia et al, 2024). This minimization and pathologization of people with higher weight anorexia can delay identification and treatment, trigger relapses and hinder people's recovery (Harrop et al, 2023) which is deeply concerning as while termed 'atypical', higher weight anorexia is as common if not more so than anorexia nervosa (Harrop et al, 2021).…”