Where does purging disorder lie on the symptomatologic and personality continuum when compared to other eating disorder subtypes? Implications for the DSM

There is nothing as inconsistent as the OSFED diagnostic criteria

Atypical anorexia nervosa (AAN), purging disorder (PD), night eating syndrome (NES), and subthreshold bulimia nervosa and binge-eating disorder (Sub-BN/BED) are the five categories that comprise the 'Other Specified Feeding or Eating Disorder' (OSFED) category in the Diagnostic and Statistical Manual for Mental Disorders (DSM-5). In this review, we examine problems with the diagnostic criteria that are currently proposed for the five OSFED types. We conclude that the existing diagnostic criteria for OSFED are deficient and fall short of accurately describing the complexity and individuality of those with these eating disorders (EDs). Therefore, to enhance the quality of life of people with OSFED, diagnostic criteria for the condition should be applied uniformly in clinical and research settings.

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

OBJECTIVE

There is a lack of consensus in defining "significant weight loss" when diagnosing atypical anorexia nervosa (atypical AN) and no guidelines exist for setting target weight (TW). The current study aimed to identify community providers' practices related to the diagnosis of atypical AN and the determination of TW. A secondary aim was to evaluate whether professional discipline impacted "significant weight loss" definitions.

METHOD

A variety of providers (N = 141; 96.4% female) completed an online survey pertaining to diagnostic and treatment practices with atypical AN. Descriptive statistics were computed to characterize provider-based practices and Fisher's exact tests were used to test for differences in diagnostic practices by professional discipline. Thematic analysis was used to examine open-ended questions.

RESULTS

Most (63.97%) providers diagnosed atypical AN in the absence of any weight loss if other AN criteria were met, but doctoral-level psychologists and medical professionals were less likely to do so compared to nutritional or other mental health professionals. Most providers found weight gain was only sometimes necessary for atypical AN recovery. Qualitative responses revealed providers found atypical AN to be a stigmatizing label that was not taken seriously. Providers preferred to use an individualized approach focused on behaviors, rather than weight when diagnosing and treating atypical AN.

DISCUSSION

Lack of diagnostic clarity and concrete treatment guidelines for atypical AN may result in substantial deviations from the DSM-5-TR criteria in real-world practice. Clinically useful diagnostic definitions for restrictive eating disorders and evidence-based treatment guidelines for TW and/or other relevant recovery metrics are needed.

PUBLIC SIGNIFICANCE

The current study found variability in how community providers diagnose and determine target recovery weight for atypical anorexia nervosa (atypical AN). Many providers viewed the diagnosis of atypical AN as stigmatizing and preferred to focus on behaviors, rather than weight. This study underscores the importance of creating a clinically useful diagnostic definition and guidelines for recovery for atypical AN backed by empirical evidence that providers may implement in practice.

Distinguishing probable atypical anorexia nervosa from weight loss alone in a national sample of U.S. Military Veterans: Disentangling the roles of weight suppression and cognitive concerns

OBJECTIVE

Veterans are at high risk for eating disorders (EDs), and specifically for atypical anorexia nervosa (atypical AN). The current study aimed to better understand this under-studied disorder and how it differs from weight loss without ED cognitive features.

METHOD

Secondary analyses were conducted with data from a national study of Veterans (N = 882, 49.4% women). Participants were categorized into four mutually exclusive groups using the Eating Disorder Diagnostic Scale 5: probable atypical AN, a cognitive concerns group (Cog Only), a weight suppressed group (WS Only), and a no ED control group. Adjusted regression models were used to compare groups on measures of eating pathology and mental health. Three weight suppression thresholds (5%, 10%, and 15%) for probable atypical AN were also tested.

RESULTS

The sample was comprised of 12% probable atypical AN, 23.6% Cog Only, 16.3% WS Only, and 48.1% Control. The probable atypical AN group was most like the Cog Only group except for higher levels of dietary restraint. Atypical AN fared worse and was least like the Control group followed by the WS Only group. All weight suppression thresholds significantly predicted dietary restraint, with 5% being the best predictor.

DISCUSSION

Results found that probable atypical AN is a distinct clinical entity and that the exact weight suppression threshold associated with atypical AN is less important than having any weight suppression. Findings highlight the clinical significance of atypical AN and the importance of gaining a better understanding of how to address this clinical entity.

PUBLIC SIGNIFICANCE

Atypical anorexia nervosa is a relatively underexamined but highly prevalent eating disorder in the Veteran population. Results show that ED cognitive features are more closely linked to clinically significant eating pathology and poor mental health than weight suppression alone suggesting that negative thinking about weight gain and appearance, regardless of the presence or severity of weight loss, may signal the need for specialized intervention.

Examining negative urgency as a predictor of eating disorder maintenance in purging syndromes

OBJECTIVES

Negative urgency is associated with short-term maintenance of binge eating and purging in unselected samples. The current study used an eating disorder sample to test the hypothesis that negative urgency maintains bulimia nervosa (BN) and purging disorder (PD) at long-term follow-up. It was also hypothesized that baseline differences in negative urgency between BN and PD would remain at follow-up.

METHODS

Secondary analyses were conducted on a sample of women who engaged in recurrent self-induced vomiting (n = 68; 52.9% BN; 47.1% PD). Women completed diagnostic interviews and questionnaires at baseline and at a mean (SD) of 5.95 (1.58) years follow-up (range = 2.51-9.62; retention rate = 75%).

RESULTS

Negative urgency did not predict eating disorder diagnostic status, recovery status, or global eating pathology at follow-up (p's = .06-.83). There were no significant differences in negative urgency across women with BN and PD at follow-up (p = .16). However, post hoc analyses indicated that negative urgency was not stable across time (ICC = .102). Increases in negative urgency from baseline to follow-up were associated with greater global eating pathology at follow-up (p = .002).

CONCLUSION

Results suggest negative urgency does not predict long-term eating disorder maintenance. Negative urgency may not be a stable personality trait but rather an indicator of overall poor emotion regulation. Future research should confirm that changes in negative urgency predict chronic eating pathology over long durations of follow-up in women who have increasing negative urgency across time.

A systematic review comparing atypical anorexia nervosa and anorexia nervosa

OBJECTIVE

A description of atypical anorexia nervosa (atypical AN) was provided in DSM-5 in 2013 and a sizable literature has since developed describing the clinical features of individuals with atypical AN and comparing them to those of individuals with anorexia nervosa (AN) and those of healthy individuals. The purpose of this study was to conduct a systematic review of this literature.

METHOD

A systematic review following PRISMA guidelines was conducted of studies published since 2013 that compared the clinical characteristics of individuals with atypical AN to those of individuals with AN and/or healthy controls. Meta-analyses were conducted when similar measures were reported in three or more studies.

RESULTS

Twenty-four publications met criteria for inclusion. Their results indicated that the level of eating disorder-specific psychopathology is significantly higher among individuals with atypical AN than among controls and as high or higher as among individuals with AN while levels of non-eating disorder psychopathology are similar. Individuals with atypical AN experience many of the physiological complications associated with AN, but some complications appear less frequent.

DISCUSSION

The psychological symptoms and physiological complications of individuals with atypical AN are generally similar to those of individuals with AN, although there may be differences in the frequency of some physical complications. Little information is available on the course, outcome, and treatment response of individuals with atypical AN. In addition, full diagnostic criteria for atypical AN have not been developed, and the nosological relationship of atypical AN to established eating disorders such as bulimia nervosa is unclear.

PUBLIC SIGNIFICANCE

Atypical anorexia nervosa as described in the DSM-5 identifies individuals with many of the psychological characteristics of typical anorexia nervosa who, despite significant weight loss, are not underweight. The current systematic review found that the psychological symptoms and physiological characteristics of individuals with atypical AN are generally similar to those of individuals with AN, although there may be differences in the frequency of some physical complications.

Evaluating the predictive validity of purging disorder by comparison to bulimia nervosa at long-term follow-up

OBJECTIVE

The current study sought to examine the predictive validity of the purging disorder diagnosis at long-term follow-up by comparing naturalistic outcomes with bulimia nervosa.

METHOD

Women with purging disorder (N = 84) or bulimia nervosa (N = 133) who had completed comprehensive baseline assessments as part of one of three studies between 2000 and 2012 were sought for follow-up assessment. Nearly all (94.5%) responded to recruitment materials and 150 (69% of sought sample; 83.3% non-Hispanic white; 33.40 [7.63] years old) participated at an average of 10.59 (3.71) years follow-up. Participants completed the Eating Disorder Examination, the Structured Clinical Interview for DSM-IV, and a questionnaire battery. Diagnostic groups were compared on eating disorder (illness status, recovery status, and eating pathology) and related outcomes. Group differences in predictors of outcome were explored.

RESULTS

There were no significant differences in eating disorder presence (p = .70), recovery status (p = .87), and level of eating pathology (p = .17) between diagnostic groups at follow-up. Post hoc equivalence tests indicated group differences were smaller than a medium effect size (p's ≤ .005). Groups differed in diagnosis at follow-up (p = .002); diagnostic stability was more likely than cross-over to bulimia nervosa for women with baseline purging disorder (p = .004).

DISCUSSION

Although purging disorder and bulimia nervosa do not differ in long-term outcomes, the relative stability in clinical presentation suggests baseline group differences in clinical presentation may be useful in augmenting treatments for purging disorder.

PUBLIC SIGNIFICANCE STATEMENT

While purging disorder is classified as an "other specified" eating disorder, individuals who experience this disorder have comparable negative long-term outcomes as those with bulimia nervosa. This highlights the importance of screening for and treating purging disorder as a full-threshold eating disorder.