A proposed trumping scheme for other specified feeding or eating disorder: Comment on Walsh et al., 2023

Guidelines for Rigorous and Reproducible Research on Other Specified Feeding or Eating Disorder: Commentary on Dang et al. (2024)

Dang et al.'s review concludes that atypical anorexia nervosa (atypical AN), purging disorder (PD), and night eating syndrome (NES) are clinically significant and severe eating disorders (EDs). However, findings are unlikely to alter their status in future editions of the DSM due to limitations in the literature to date. Guidelines are offered to promote rigorous and reproducible research on other specified feeding or eating disorder OSFED. First, published research diagnostic criteria for atypical AN, PD, and NES should be consistently used to ensure findings across studies reflect the same conditions. Second, operational definitions are recommended for "recurrent" as at least twice within a 3-month period, minimum duration as at least 1 month, and "significant weight loss" as >5% BMI reduction within 1 month. Third, Thomas's and Gydus's trumping scheme for differential diagnosis of OSFED subcategories is endorsed but should prioritize identifying treatment targets based on medical morbidity over mirroring existing diagnostic algorithms. Fourth, a systematic approach for establishing clinical significance is recommended that explicitly notes medical risk associated with malnutrition, purging and nonpurging behaviors, and relevance of marked distress related to binge eating and body image disturbance. Adoption of these guidelines will facilitate necessary research on clinical utility.

Atypical anorexia nervosa: A scoping review to determine priorities in research and clinical practice

BACKGROUND

There is currently a limited understanding of the identification, nature, and treatment of Atypical Anorexia Nervosa (AAN). Recent systematic reviews have identified only small numbers of candidate papers, and some areas lack any meaningful review so far - particularly treatment outcomes. A key issue is the lack of clarity in the literature regarding the definition of weight loss criteria.

OBJECTIVES

This scoping review aimed to determine the nature and extent of our knowledge of AAN, in order to assist in the development of future systematic reviews and meta-analyses, as well as indicating what further research is needed.

METHOD

Following the identification of 6747 records, 317 records using the term AAN or a defined equivalent were identified from six databases, including the 'grey' literature.

RESULTS

Of the 317 studies, 111 provided participant characteristics, and only 10 provided discrete treatment outcomes. Each of these subsets of the data are tabulated and supported with supplementary material, so that future systematic reviewers can access this resource.

DISCUSSION

The pattern and content of the existing studies allows recommendations to be made regarding future reviews, research and clinical practice. There is a particular need for clear weight/weight loss criteria and adequate interventions.

A living experience proposal for the co-occurring diagnosis of avoidant/restrictive food intake disorder and other eating disorders

The eating and feeding disorder section of the Diagnostic and Statistical Manual of Mental Disorders 5 Text Revision (DSM-5-TR) is organized by a diagnostic algorithm that limits the contemporaneous assignment of multiple eating disorder diagnoses. Avoidant/restrictive food intake disorder (ARFID) is a disturbance in food intake typically associated with lack of interest in food, food avoidance based on sensory characteristics, and/or fear of aversive consequences from eating. According to the DSM-5-TR, an ARFID diagnosis cannot be made when weight or shape disturbances are present, and ARFID cannot be co-diagnosed with other eating disorders characterized by these disturbances. However, emerging evidence from both clinical and lived experience contexts suggests that the co-occurrence of ARFID with multiple other types of eating disorders may be problematically invisibilized by this trumping scheme. The diagnostic criteria for ARFID can contribute to inappropriate diagnosis or exclusion from diagnosis due to excessive ambiguity and disqualification based on body image disturbance and other eating disorder pathology, even if unrelated to the food restriction or avoidance. This harmfully limits the ability of diagnostic codes to accurately describe an individual's eating disorder symptomatology, impacting access to specialized and appropriate eating disorder care. Therefore, revision of the DSM-5-TR criteria for ARFID and removal of limitations on the diagnosis of ARFID concurrent to other full-syndrome eating disorders stands to improve identification, diagnosis, and support of the full spectrum of ARFID presentations.

Prospective 2-Year Course and Predictors of Outcome in Avoidant/Restrictive Food Intake Disorder

OBJECTIVE

To evaluate the 2-year course and outcomes of full and subthreshold avoidant/restrictive food intake disorder (ARFID) in youth aged 9 to 23 years at baseline using a prospective longitudinal design to characterize the remission and persistence of ARFID, evaluate diagnostic crossover, and identify predictors of outcome. Greater severity in each ARFID profile-sensory sensitivity, fear of aversive consequences, and lack of interest-was hypothesized to predict greater likelihood of illness persistence, controlling for age, sex, body mass index percentile, ARFID treatment status, and baseline diagnosis.

METHOD

Participants (N = 100; age range, 9-23 years; 49% female; 91% White) were followed over 2 years. The Pica, ARFID, and Rumination Disorder Interview was used across 3 time points (baseline, year 1, year 2) to measure the severity of each ARFID profile and evaluate illness persistence or remission, and the Eating Disorder Assessment for DSM-5 was used to evaluate diagnostic crossover.

RESULTS

Across the 2-year follow-up period, half the participants persisted with their original diagnosis, and 3% of participants experienced a diagnostic shift to anorexia nervosa. Greater severity in the sensory sensitivity and lack of interest profiles was associated with higher likelihood of ARFID persistence at year 1 only; greater severity in the fear of aversive consequences profile was associated with higher likelihood of ARFID remission at year 2 only.

CONCLUSION

Findings underscore the distinctiveness of ARFID from other eating disorders and emphasize its persistence over 2 years. Results also highlight the predictive validity and prognostic value of the ARFID profiles (ie, sensory sensitivity, fear of aversive consequences, lack of interest).

Examining the placement of atypical anorexia nervosa in the eating disorder diagnostic hierarchy relative to bulimia nervosa and binge-eating disorder

OBJECTIVE

Some individuals meet the criteria for atypical anorexia nervosa and another eating disorder simultaneously. The current study evaluated whether allowing a diagnosis of atypical anorexia nervosa to supersede a diagnosis of bulimia nervosa (BN) or binge-eating disorder (BED) provided additional information on psychological functioning.

METHODS

Archival data from 650 university students (87.7% female, 69.4% white) who met Eating Disorder Diagnostic Survey for DSM-5 eating disorder criteria and completed questionnaires assessing quality of life, eating disorder-related impairment, and/or eating pathology at a single time point. Separate regression models used diagnostic category to predict quality of life and impairment. Two diagnostic schemes were used: the DSM-5 diagnostic scheme and an alternative scheme where atypical anorexia nervosa superseded all diagnoses except anorexia nervosa. Model fit was compared using the Davidson-Mackinnon J test. Analyses were pre-registered (https://osf.io/2ejcd).

RESULTS

Allowing an atypical anorexia nervosa diagnosis to supersede a BN or BED diagnosis provided better fit to the data for eating disorder-related impairment (p = .02; n = 271), but not physical, psychological, or social quality of life (p's ≥ .33; n = 306). Allowing an atypical anorexia nervosa diagnosis to supersede a BN or BED diagnosis provided a better fit in cross-sectional models predicting purging (p = .02; n = 638), but not body dissatisfaction, binge eating, restricting, or excessive exercise (p's ≥ .08; n's = 633-647).

DISCUSSION

The current data support retaining the DSM-5 diagnostic scheme. More longitudinal work is needed to understand the predictive validity of the atypical anorexia nervosa diagnosis.

PUBLIC SIGNIFICANCE

The current study examined how changes to the diagnostic categories for eating disorders may change how diagnoses are associated with quality of life and impairment. Overall, findings suggest that the diagnostic hierarchy should be maintained.

Affective processes underlying restrictive eating in atypical anorexia nervosa: Comparisons to anorexia nervosa and bulimia nervosa using ecological momentary assessment

OBJECTIVE

Certain symptom and risk/maintenance factor similarities between individuals with atypical anorexia nervosa (AN) and 'typical' AN have been documented, but few studies have investigated how atypical AN compares to bulimia nervosa (BN). Further, the role of affective mechanisms in maintaining restrictive eating in atypical AN has not been examined. The current study investigated whether atypical AN resembles AN and/or BN on affect-related processes using questionnaires and ecological momentary assessment (EMA).

METHOD

Women with atypical AN (n = 24), AN-restrictive subtype, (n = 27), AN-binge eating/purging subtype (n = 34), and BN (n = 58) completed questionnaires measuring depressive symptoms and emotion regulation difficulties. They also completed a 14-day EMA protocol during which they reported negative and positive affect and skipped meals five times/day (signal-contingent surveys) and restrictive eating after meals/snacks (event-contingent surveys).

RESULTS

Diagnostic groups generally did not differ on questionnaire measures nor affective patterns surrounding restrictive eating behaviors. Momentary changes in affect did not predict or follow restriction at meals/snacks, though higher momentary negative affect ratings predicted skipped meals, and higher positive affect was reported after skipped meals. Greater average negative affect and lower average positive affect predicted both restrictive eating behaviors.

DISCUSSION

Across diagnoses, reductions in food intake do not appear to be influenced by momentary changes in affect, though skipping meals may serve an emotion regulation function. Atypical AN seems to resemble AN and BN on affective processes underlying restrictive eating, raising further questions regarding the unique diagnosis of atypical AN.

PUBLIC SIGNIFICANCE

Though atypical anorexia appears to strongly resemble anorexia nervosa, it is less clear how this disorder relates to bulimia nervosa. It is further unknown whether affective-related processes underlie restrictive eating in atypical anorexia nervosa, and how these processes compare to those in anorexia nervosa and bulimia nervosa. Results suggest that atypical anorexia does not differ from anorexia nervosa or bulimia nervosa on emotion-related measures, nor in affective patterns surrounding restrictive eating behaviors.

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

OBJECTIVE

Anorexia nervosa (AN) is a serious illness with a high mortality rate and multiple physiological complications. The vague definition of atypical AN allows for subjective interpretation. This retrospective study aimed to focus future research on the operational definition of atypical AN by examining four factors associated with atypical AN at admission to higher level of care treatment.

METHODS

Adults with atypical AN (n = 69) were examined within sample analyses among four groups: (1) >10% versus ≤10% weight loss; (2) weight loss within the previous 3 months versus >3 months; (3) engaging in purging behaviors versus absence of purging behaviors; and (4) endorsing versus not endorsing significant cognitive aspects of AN.

RESULTS

Patients with atypical AN endorsed elevated ED cognitions on the Eating Disorder Examination-Questionnaire and depressive symptoms; a lack of association was found between weight loss severity and weight loss time frame with depressive symptoms, eating concern, and restraint. Purging behavior was associated with a higher expected body weight percentage (%EBW) and dietary restraint, while greater AN cognitions were associated with a higher EBW and weight loss percentage. Few patients demonstrated bradycardia, hypophosphatemia, or amenorrhea.

DISCUSSION

This study demonstrated the severity of ED cognitions and depressive symptoms in this atypical AN sample and provided directions for future studies in the nosology of atypical AN. It may be important to distinguish between individuals with atypical AN who are purging and those who are not. Atypical AN was associated with a low frequency of physiological disturbances.

PUBLIC SIGNIFICANCE

This study provides further clarification regarding the operational definition of atypical AN; currently, a constellation of symptoms under Other Specified Feeding or Eating Disorders. This study was consistent with previous research in reporting severe eating disorder cognitions in adults with atypical AN, and noted the potential importance of distinguishing a purging distinction. A minority of patients in this study had physiological impairments.

Oxytocin response to food intake in avoidant/restrictive food intake disorder

OBJECTIVE

To investigate the response of anorexigenic oxytocin to food intake among adolescents and young adults with avoidant/restrictive food intake disorder (ARFID), a restrictive eating disorder characterized by lack of interest in food or eating, sensory sensitivity to food, and/or fear of aversive consequences of eating, compared with healthy controls (HC).

DESIGN

Cross-sectional.

METHODS

A total of 109 participants (54 with ARFID spectrum and 55 HC) were instructed to eat a ∼400-kcal standardized mixed meal. We sampled serum oxytocin at fasting and at 30-, 60-, and 120-min postmeal. We tested the hypothesis that ARFID would show higher mean oxytocin levels across time points compared with HC using a mixed model ANOVA. We then used multivariate regression analysis to identify the impact of clinical characteristics (sex, age, and body mass index [BMI] percentile) on oxytocin levels in individuals with ARFID.

RESULTS

Participants with ARFID exhibited greater mean oxytocin levels at all time points compared with HC, and these differences remained significant even after controlling for sex and BMI percentile (P = .004). Clinical variables (sex, age, and BMI percentile) did not show any impact on fasting and postprandial oxytocin levels among individuals with ARFID.

CONCLUSIONS

Consistently high oxytocin levels might be involved in low appetite and sensory aversions to food, contributing to food avoidance in individuals with ARFID.