A systematic review comparing atypical anorexia nervosa and anorexia nervosa

Momentary physiological indices related to eating disorders: A systematic and methodological review

Eating disorders (ED) are serious psychiatric illnesses, with no everyday support to intervene on the high rates of relapse. Understanding physiological indices that can be measured by wearable sensor technologies may provide new momentary interventions for individuals with ED. This systematic review, searching large databases, synthesises studies investigating peripheral physiological (PP) indices commonly included in wearable wristbands (heart rate [HR], heart rate variability [HRV], electrodermal activity [EDA], peripheral skin temperature [PST], and acceleration) in ED. Inclusion criteria included: (a) full peer-reviewed empirical articles in English; (b) human participants with active ED; and (c) containing one of five wearable physiological measures. Kmet risk of bias was assessed. Ninety-four studies were included (Anorexia nervosa [AN; N = 4418], bulimia nervosa [BN; N = 916], binge eating disorder [BED; N = 1604], other specified feeding and eating disorders [OSFED; N = 424], and transdiagnostic [N = 47]). Participants with AN displayed lower HR and EDA and higher HRV compared to healthy individuals. Those with BN showed higher HRV, and lower EDA and PST compared to healthy individuals. Other ED and Transdiagnostic samples showed mixed results. PP differences are indicated through various assessments in ED, which may suggest diagnostic associations, although more studies are needed to validate observed patterns. Results suggest important therapeutic potential for PP in ED, and larger studies including diverse participants and diagnostic groups are needed to fully uncover their role in ED.

Associations between presenting weight and premorbid weight and the medical sequelae in hospitalized youth with anorexia nervosa or atypical anorexia nervosa

PURPOSE

To identify unique treatment considerations for youth with anorexia nervosa (AN) or atypical anorexia nervosa (AAN) and premorbid overweight or obesity, we examined unique relationships between premorbid and presenting weight status and medical sequelae in youth with AN/AAN requiring medical hospitalization.

DESIGN AND METHODS

We performed a retrospective study of 150 youth aged mean [SD] of 14.1[2.3] years, hospitalized for AN/AAN. Independent t-tests and Fischer's exact tests assessed differences in demographic and clinical characteristics by premorbid weight status. Logistic regressions assessed associations between premorbid and presenting weight status and vital sign or laboratory abnormalities.

RESULTS

Compared to youth with premorbid 'normal' weights, youth with premorbid overweight/obesity demonstrated greater percent (p = .042) and faster rate (p < .001) of weight loss and had 10.9 times the odds of having anemia (p = .025). Youth with AN (<5th percentile for body mass index [BMI]) were more likely to experience hypoglycemia (p < .018) than youth with AAN (≥5th percentile BMI). Greater percent of weight loss significantly predicted bradycardia (p < .001) and hypoglycemia (p = .002), independent of premorbid or presenting weight status.

CONCLUSION

Acute medical management of AN/AAN should be commensurate for hospitalized patients, regardless of premorbid weight status. However, those with more significant weight loss and those presenting as underweight may warrant particular monitoring for complications such as bradycardia and hypoglycemia.

PRACTICE IMPLICATIONS

In youth with AN/AAN, high percent of weight loss warrants closer monitoring for medical complications during hospitalization. Those with premorbid overweight/obesity may need additional monitoring for anemia, as there may be additional contributors to anemia aside from malnutrition.

Is there a basis for a weight cut-off point? A large-scale investigation of atypical anorexia and anorexia nervosa subtypes among patients at a residential treatment centre

OBJECTIVE

There is debate surrounding how to differentiate between anorexia nervosa (AN) and atypical AN (atypAN) as diagnostic entities, and whether a distinction based on BMI is warranted. Better understanding eating disorder (ED) and emotional symptoms across atypAN and AN subtypes [AN-restricting (AN-R), AN-binge/purge (AN-BP)], with and without controlling for BMI, can elucidate how atypAN differs from AN subtypes and whether there is a basis for a BMI cut-off.

METHODS

1810 female patients at an ED treatment centre completed intake surveys. ANCOVAs assessed differences across AN-R (n = 853), AN-BP (n = 726), and atypAN (n = 231) groups on ED, depressive, and anxiety symptoms, anxiety sensitivity, experiential avoidance, and mindfulness, with and without controlling for BMI.

RESULTS

Relative to AN-R, atypAN and AN-BP groups endorsed significantly higher ED and depressive symptoms, anxiety sensitivity, experiential avoidance, and significantly lower mindfulness (all p < 0.001), but atypAN and AN-BP groups did not differ from one another. When controlling for BMI, all previously significant differences between atypAN and AN-R did not remain significant.

CONCLUSION

Individuals with atypAN who have a higher BMI experience more pronounced ED and emotional symptoms, suggesting that relying solely on BMI as a marker of illness severity may be problematic.

A prospective observational study comparing rates of medical instability between adolescents with typical and atypical anorexia nervosa

BACKGROUND

Recognition of atypical anorexia nervosa (AAN) has challenged underweight as a defining factor of illness severity in anorexia nervosa (AN). The present study aimed to compare rates of medical instability in adolescents with underweight (AN) and non-underweight (AAN) anorexia nervosa.

METHODS

The study examined assessment data from specialist eating disorder services in the UK between January and December 2022. Participants (n = 205) aged 11-18 years were recruited across eight eating disorder clinics and diagnosed with AN (n = 113) or AAN (n = 92) after clinical assessment. Parameters associated with risk of medical instability were compared between AN and AAN groups, using t tests and regression analysis.

RESULTS

Rates of bradycardia and hypotension did not differ significantly between AN and AAN groups (p = 0.239 and p = 0.289). Although white blood cell counts were lower in the AN group, rates of leukopaenia could not be statistically compared as a result of there being too few counts in at least one group. No incidences of hypophosphataemia were found in the sample. A significant regression equation was found for percentage median body mass index, but not rate of weight loss, as a predictor of blood pressure, serum phosphorous and magnesium.

CONCLUSIONS

Our findings indicate that medical instability occurs across a range of body weights in young people with AN and AAN. Although certain parameters of risk such as blood pressure, serum phosphorous and magnesium may be worsened at lower weight, both AN and AAN are serious mental health conditions that can lead to medical instability.

A systematic review of eating disorders and family functioning

The purpose of the current review was to address four questions: 1) Are there differences in family functioning or family environment among patients with different eating disorder (ED) diagnoses? 2) Are there differences in the perception of family functioning or family environment among different family members? 3) Is family functioning or family environment related to ED symptomatology? 4) Does family functioning or family environment change as a result of ED treatment? and 4a) If so, does this impact ED treatment outcome? Although most studies found no differences among ED diagnostic groups, those that did generally found worse family functioning among those with binge/purge symptoms than among those with the restricting subtype of anorexia nervosa. Differences in perceptions of family functioning among family members were found, with patients generally reporting worse functioning than their parents. Worse family functioning was generally found to be related to worse ED symptoms. The variety of treatment approaches and different assessments of outcome made it somewhat unclear whether family functioning consistently improves with ED treatment. More research is needed on family functioning and EDs, particularly in understudied groups such as males, and those with ED diagnoses other than anorexia nervosa or bulimia nervosa.

Menstrual characteristics of atypical anorexia nervosa

OBJECTIVE

While menstrual irregularities are acknowledged in restrictive-type eating disorders (EDs), the menstrual characteristics specific to atypical anorexia nervosa (AAN) remain inadequately defined. This study aims to compare the menstrual features of anorexia nervosa (AN) and AAN.

METHOD

Adolescents diagnosed with AN or AAN who exhibited secondary amenorrhoea at presentation and had their menstrual cycles restored during follow-up were eligible for this study. Clinical and menstrual data at admission and during follow-up were obtained from patient files, and compared between the AN and AAN cohorts.

RESULTS

The study included a total of 77 patients (38 with AN and 39 with AAN). The extent of weight loss and the disease duration until the onset of amenorrhoea were comparable in the two groups. However, the duration of illness and the time since the last menstrual period at admission were shorter in the AAN group. Moreover, amenorrhoea manifested at a higher body mass index, and the return of menses occurred more rapidly with less weight gain in the AAN group after the onset of clinical follow-up. Additionally, the AAN group exhibited a shorter overall duration of amenorrhoea.

CONCLUSIONS

This study highlights the significance of recognising amenorrhoea in restrictive disorders, even when individuals maintain a normal weight. The faster return of menstrual cycles and shorter duration of amenorrhoea observed in adolescents with AAN emphasise the significance of early diagnosis and prompt initiation of treatment. Regardless of the patient's presenting complaint and weight status, obtaining a comprehensive ED history is essential when addressing concerns regarding amenorrhoea or menstrual irregularities.

Comparing changes in eating disorder psychopathology and comorbid symptoms over treatment in anorexia nervosa and atypical anorexia nervosa in a partial hospitalization program

OBJECTIVE

The objective of this study is to compare treatment trajectories in anorexia nervosa (AN) and atypical AN.

METHOD

Adolescents and adults with AN (n = 319) or atypical AN (n = 67) in a partial hospitalization program (PHP) completed diagnostic interviews and self-report questionnaires measuring eating disorder (ED), depression, and anxiety symptoms throughout treatment.

RESULTS

Premorbid weight loss did not differ between diagnoses. Individuals with atypical AN had more comorbid diagnoses, but groups did not differ on specific diagnoses. ED psychopathology and comorbid symptoms of depression/anxiety did not differ at admission between groups nor did rate of change in ED psychopathology and comorbid symptoms of depression/anxiety from admission to 1-month. From admission to discharge, individuals with atypical AN had a faster reduction in ED psychopathology and comorbid symptoms of depression and anxiety (ps < 0.05; rs = 0.01-0.32); however, there were no group differences in ED psychopathology or depression symptoms at discharge (ps>.50; ds = .01-.30). Individuals with atypical AN had lower anxiety at discharge compared to individuals with AN (p = 0.05; d = .4). Length of stay did not differ between groups (p = 0.11; d = .21).

DISCUSSION

Groups had similar ED treatment trajectories, suggesting more similarities than differences. PHP may also be effective for AAN.

PUBLIC SIGNIFICANCE

This study supports previous research that individuals with AN and atypical AN have more similarities than differences. Results from this study indicate that individuals with AN and atypical AN have similar treatment outcomes for both ED psychopathology and depressive symptoms; however, individuals with atypical AN have lower anxiety symptoms at discharge compared to individuals with AN. AN and atypical AN also have more symptom similarity at admission and throughout treatment, which challenges their current designation as distinct disorders.

Weight gain and eating disorder symptoms among individuals with atypical anorexia nervosa

OBJECTIVE

The purpose of this study was to examine the association between weight gain and eating disorder (ED) symptoms among adults receiving treatment for atypical anorexia nervosa (AAN), to determine whether those who had a higher percent of expected body weight (%EBW) at discharge exhibited lower ED symptoms than those who gained less weight, and to compare this group to a matched sample of patients with anorexia nervosa (AN).

METHOD

Participants were 96 adults receiving treatment at an ED treatment facility between December 2020 and May 2023. The Eating Disorder Examination-Questionnaire (EDE-Q) was completed at admission and discharge, and %EBW was obtained at admission and discharge.

RESULTS

All EDE-Q subscale scores improved from admission to discharge for patients with AAN and patients with AN. Neither %EBW at discharge nor weight gain were associated with EDE-Q subscale scores for those with AAN. For patients with AN, %EBW at discharge and weight gain were associated with EDE-Q Restraint at discharge.

CONCLUSIONS

Weight restoring to a higher level and gaining more weight were not associated with EDE-Q scores at discharge for AAN. Further research is needed to determine how weight restoration using intensive treatment settings affects remission and recovery in patients with AAN.

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.

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.

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.

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.

Few differences in psychiatric comorbidities and treatment response among people with anorexia nervosa and atypical anorexia nervosa

OBJECTIVE

Little is known about how individuals with atypical anorexia nervosa (AN) respond to eating disorder (ED) treatment in a partial hospitalization program (PHP), nor how certain factors such as trauma, childhood abuse, psychiatric comorbidity, and suicidal thoughts and behaviors might contribute to poor treatment outcomes. Thus, the current study (1) compares prevalence of these factors between individuals with AN and atypical AN upon admission to an ED PHP, (2) compares PHP treatment response between groups, and (3) investigates whether experiencing these factors impacts treatment outcomes.

METHOD

We conducted a retrospective chart review of young adults admitted to a PHP with AN (n = 95) and atypical AN (n = 59). Histories of psychiatric comorbidities and adverse childhood experiences were obtained from initial psychiatric evaluations. ED symptoms were assessed at intake and discharge with the Eating Disorder Examination-Questionnaire (EDE-Q).

RESULTS

No significant differences were found at intake in ED symptom severity or prevalence of lifetime trauma, childhood abuse, number of psychiatric diagnoses, or suicidal thoughts and behavior. Symptomatology at discharge also did not differ between groups. Emotional abuse was significantly related to discharge shape and weight overvaluation. No other intake characteristics were significantly related to discharge symptomatology.

DISCUSSION

To our knowledge, this is the first study to compare the prevalence of comorbidities for both AN and atypical AN, as well as differential treatment outcomes for these individuals in a PHP. Results add to growing literature suggesting that, other than weight, AN and atypical AN have few properties that reliably distinguish them from one another.

PUBLIC SIGNIFICANCE

This study adds to a growing body of literature that raises questions about whether anorexia nervosa (AN) and atypical AN are truly different diagnoses. Our findings suggest these two groups present to treatment in a partial hospitalization program (PHP) with similar ED symptoms, as well as prevalence of lifetime trauma, childhood abuse, suicidal thoughts and behavior, and number of psychiatric comorbidities, and demonstrate similar treatment trajectories in PHP.

Differentiating anorexia nervosa and atypical anorexia nervosa with absolute weight cut-offs results in a skewed distribution for premorbid weight among youth

OBJECTIVE

Anorexia nervosa (AN) and atypical AN are conceptualized as distinct illnesses, despite similar characteristics and sequelae. Whereas DSM-5 differentiates youth with AN and atypical AN by the presence of clinical 'underweight' (i.e., 5th BMI percentile for age-and-sex (BMI%)), we hypothesized that using this weight cut-off to discern diagnoses creates a skewed distribution for premorbid weight.

METHOD

Participants included hospitalized youth with AN (n = 165, 43.1%) and atypical AN (n = 218, 56.9%). Frequency analyses and chi-square tests assessed the distribution of premorbid BMI z-scores (BMIz) for diagnosis. Non-parametric Spearman correlations and Stepwise Linear regressions examined relationships between premorbid BMIz, admission BMIz, and weight loss in kg.

RESULTS

Premorbid BMIz distributions differed significantly for diagnosis (p < .001), with an underrepresentation of 'overweight/obesity' (i.e., BMI% ≥ 85th) in AN. Despite commensurate weight loss in AN and atypical AN, patients with premorbid 'overweight/obesity' were 8.31 times more likely to have atypical AN than patients with premorbid BMI% < 85th. Premorbid BMIz explained 57% and 39% of the variance in admission BMIz and weight loss, respectively.

DISCUSSION

Findings support a homogenous model of AN and atypical AN, with weight loss predicted by premorbid BMI in both illnesses. Accordingly, premorbid BMI and weight loss (versus presenting BMI) may better denote the presence of an AN-like phenotype across the weight spectrum. Findings also suggest that differentiating diagnoses with BMI% < 5th requires that youth with higher BMIs lose disproportionately more weight for an AN diagnosis. This is problematic given unique treatment barriers experienced in atypical AN.

PUBLIC SIGNIFICANCE

Anorexia nervosa (AN) and atypical AN are considered distinct conditions in youth, with differential diagnosis hinging upon a presenting weight status of 'underweight' (i.e., BMI percentile for age-and-sex (BMI%) < 5th). In our study, youth with premorbid 'overweight/obesity' (BMI% ≥ 85th) disproportionately remained above this threshold, despite similar weight loss. Coupled with prior evidence for commensurate characteristics and sequelae in both diagnoses, we propose that DSM-5 differentiation of AN and atypical AN inadvertently reinforces weight stigma and may contribute to treatment disparities in atypical AN.

The role of readiness and confidence to change in the treatment of atypical anorexia nervosa and bulimia nervosa

OBJECTIVE

Atypical anorexia nervosa (AN) is a serious eating disorder that is more common in the population than AN. Despite this, people with atypical AN are less likely to be referred or admitted for eating disorder treatment and there is evidence that they are less likely to complete or benefit from existing interventions. This study examined whether baseline readiness and/or confidence moderated outcomes from 10-session cognitive behavioral therapy among people with atypical AN and bulimia nervosa (BN), and whether the impact of these variables differed between diagnoses.

METHODS

Participants (n = 67; 33 with atypical AN) were a subset from an outpatient treatment study. Linear mixed model analyses were conducted to examine whether baseline readiness and/or confidence moderated outcomes.

RESULTS

People with BN who had higher levels of readiness or confidence at baseline had steeper decreases in eating disorder psychopathology over time. There was no evidence that readiness or confidence moderated outcomes for people with atypical AN.

DISCUSSION

This study suggests that the moderators that have been identified for other eating disorders may not apply for people with atypical AN and highlights a need for future work to routinely investigate whether theoretically or empirically driven variables moderate outcomes in this little-understood population.

PUBLIC SIGNIFICANCE STATEMENT

People with bulimia nervosa with higher readiness and confidence experienced greater decreases in eating disorder symptoms than people with lower readiness and confidence when treated with cognitive behavioral therapy. These findings did not apply to people with atypical anorexia nervosa. Results demonstrate that future work is urgently required to identify helpful treatments for people with atypical anorexia nervosa as well as the variables that have a positive impact on outcomes in treatment for these individuals.

Course and outcome in individuals with atypical anorexia nervosa: Findings from the Study of Refeeding to Optimize iNpatient Gains (StRONG)

OBJECTIVE

We previously reported that participants with atypical anorexia nervosa (atypical AN) had higher historical and admission weights, greater eating disorder psychopathology, but similar rates of amenorrhea and weight suppression at baseline as compared to anorexia nervosa (AN); here, we compare 1-year outcomes.

METHOD

Weight, % median body mass index (%mBMI), Eating Disorder Examination Questionnaire (EDE-Q) scores, resumption of menses, and rehospitalizations were examined at 3, 6, and 12 months post-discharge. Analyses (N = 111) compared changes in %mBMI, weight suppression, and EDE-Q scores over time between atypical AN and AN.

RESULTS

Among the participants (48 atypical AN, 63 AN), both groups gained weight but those with atypical AN had lower gains than those with AN in %mBMI (p = .02) and greater weight suppression (p = .002) over time. EDE-Q scores improved over time, independent of weight suppression, with no significant difference between atypical AN and AN. Groups did not differ by rates of resumption of menses (80% atypical AN, 76.9% AN) or rehospitalization (29.2% atypical AN, 37.9% AN). Greater weight suppression predicted longer time to restore menses and more days of rehospitalization.

DISCUSSION

Individuals with atypical AN regained a smaller proportion of body mass and were more weight suppressed over time. Change in eating disorder cognitions, resumption of menses, and rehospitalization rates at 1-year follow-up did not differ between groups. There was no significant difference in weight suppression between groups for those who were psychologically improved at 12 months. Findings highlight limitations in our understanding of weight recovery in atypical AN. New metrics for recovery are urgently needed.

PUBLIC SIGNIFICANCE

Little is known about outcome in atypical anorexia nervosa (atypical AN). We examined recovery metrics in young people with atypical AN and anorexia nervosa (AN) 1 year after medical hospitalization. Individuals with atypical AN showed slower weight gain and remained further from their pre-illness weight. There were no differences in the rates of psychological recovery, resumption of menses, or rehospitalization. New metrics are needed to assess recovery in atypical AN.

Mental health providers' perceptions of restrictive eating disorders: Relationship with client body weight

OBJECTIVE

This study investigated whether mental health providers have different diagnostic impressions and treatment recommendations for patients with restrictive eating disorders, depending on the patient's body weight.

METHOD

Participants were given one of three versions of a vignette depicting a patient who meets DSM-5 criteria for anorexia nervosa (AN) or atypical AN with the patient's weight described as either below, within, or above the average range for her age and height. Participants were then asked to respond to a series of questions about diagnosis, symptoms, and treatment recommendations. Results were compared between the three weight conditions with the goal of better understanding how a patient's body weight may influence different aspects of participants' clinical impressions.

RESULTS

Participants given the low weight version of the vignette were more likely to identify the presenting problem as an eating disorder and to agree that the patient experienced dietary restriction and weight loss, weight gain avoidance, and body image concerns. Participants given the low weight description were also more likely to recommend specialized eating disorder treatment and medical follow-up.

DISCUSSION

Findings suggest that mental health providers were generally more responsive to restrictive eating disorder symptoms when the patient was at a lower body weight. These results are concerning because they suggest patients with atypical AN may be less likely to receive an accurate diagnosis or adequate treatment compared to underweight patients with AN, despite experiencing the same symptoms.

PUBLIC SIGNIFICANCE

Restrictive eating disorders like AN and atypical AN can cause comparable physical and psychological symptoms in people of any body weight. Despite having the same symptoms, people with a higher body weight are less likely to receive a diagnosis or treatment. This study compared mental health providers' reactions to a description of a patient with an eating disorder at different body weights and found differences in diagnosis, detection of symptoms, and treatment recommendations.

Comparisons between atypical anorexia nervosa and anorexia nervosa: Psychological and comorbidity patterns

OBJECTIVE

Literature comparing "atypical" anorexia nervosa (atypical AN) and anorexia nervosa (AN) suggests these diagnoses share significant similarities in eating disorder (ED) pathology and psychiatric comorbidities. This study evaluated potential differences in ED pathology, psychiatric comorbidity, associated mechanisms (i.e., ED fears and perfectionism), and demographic factors (i.e., ethnicity and age) between individuals with atypical AN and AN.

METHOD

Data from seven protocols were combined for a total 464 individuals diagnosed with atypical AN (n = 215) or AN (n = 249). Between-group differences in ED severity and behaviors, psychiatric comorbidities, ED fears, perfectionism, and demographic factors were assessed using t-tests, Wilcoxon rank-sum tests, and Fisher's exact test.

RESULTS

Participants with atypical AN reported higher levels of overvaluation of weight and shape than those with AN. Participants with AN scored higher on food-related fears (anxiety about eating, food avoidance behaviors, and feared concerns) and fears of social eating, as well as obsessive-compulsive symptoms. Participants with AN were more likely to identify as Asian or Pacific Islander. No other statistically significant differences were found between groups for overall ED severity, ED behaviors, psychiatric comorbidities, general ED fears, perfectionism, or demographic factors.

DISCUSSION

Overall, results support previous literature indicating limited differences between individuals with atypical AN and AN, though individuals with atypical AN reported more overvaluation of weight and shape and those with AN reported higher food and social eating fears and obsessive-compulsive symptoms. Relatively few overall differences between atypical AN and AN highlight the importance of exploring dimensional conceptualizations of AN as an alternative to the current categorical conceptualization.

PUBLIC SIGNIFICANCE

This study assessed differences among individuals with atypical anorexia nervosa and anorexia nervosa in eating disorder severity and behaviors, comorbid psychiatric diagnoses, associated mechanisms, and demographic factors. Few differences emerged, though participants with atypical anorexia nervosa reported more overvaluation of weight and shape, while those with anorexia nervosa reported more food and social eating fears and higher obsessive-compulsive symptoms. Results support exploration of these diagnoses as a spectrum disorder.

Greater rate of weight loss predicts paediatric hospital admission in adolescent typical and atypical anorexia nervosa

Hospital admissions for eating disorders (ED) are rapidly increasing. Limited research exists evidencing the factors that lead to hospital admissions or their outcomes. The current study aimed to identify predictors of hospital admission in adolescents with anorexia nervosa (AN) or atypical anorexia nervosa (AAN). Prospective observational study including participants (n = 205) aged 11-18 and diagnosed with AN or AAN at initial ED assessment, across eight London clinics. Physical health parameters at assessment, including heart rate, blood pressure, temperature and rate of weight loss, were compared between adolescents who were admitted to a paediatric ward following assessment and those who were not admitted. The mean rate of weight loss prior to assessment was significantly higher, and mean energy intake significantly lower, in the admitted vs not admitted groups (1.2 vs 0.6kg/week, p < 0.001 and 565 kcal/day vs 857 kcal/day, p < 0.001), independent of degree of underweight. No significant differences were identified between groups in all other parameters of physical risk. Underweight adolescents with AN were equally likely to be admitted as non-underweight adolescents with AAN.  Conclusion: This study provides evidence on predictors of hospital admission, from a sample representing the London area. The assessment of weight loss speed, duration and magnitude are recommended as priority parameters that inform the risk of deterioration and the likelihood of hospital admission in adolescent AN and AAN. Further research investigating outcomes of these hospital admission is needed. What is Known: • Hospital admissions for eating disorders (ED) are rapidly increasing. • Limited research exists evidencing the factors that lead to hospital admissions, or their outcomes. What is New: • This study provides evidence on predictors of hospital admission in young people with typical and atypical anorexia nervosa. • Weight loss speed, duration, and magnitude are recommended as priority parameters that inform the risk of deterioration and the likelihood of hospital admission in this patient group.

Comparing the knowledge, attitudes, and practices of pediatric and family medicine clinicians toward atypical anorexia nervosa versus anorexia nervosa

OBJECTIVE

To investigate the knowledge, attitudes, and current practices of adolescent primary care providers regarding the epidemiology, clinical features, and diagnosis of atypical anorexia nervosa (AN) compared to AN.

METHODS

An online survey was sent to the Pediatric and Family Medicine clinicians who provide medical care to adolescents. Statistical analyses compared differences in responses to questions about atypical AN versus AN.

RESULTS

Relative to AN, participants (n = 67) were significantly less familiar with atypical AN, less likely to consider a diagnosis of atypical AN, less comfortable identifying atypical AN, less likely to counsel patients with atypical AN on health risks, less likely to refer patients with atypical AN to a specialist, and less likely to correctly identify atypical AN. Clinicians with more years in medical practice reported a significantly larger gap in familiarity between AN and atypical AN than clinicians with less than 5 years of practice.

CONCLUSIONS

Providers who care for adolescents appear to be less familiar with and less likely to identify atypical AN compared to AN. This knowledge gap may be more pronounced among clinicians with more years practicing medicine due to the novelty of atypical AN as a diagnosis. Lack of knowledge surrounding atypical AN risk factors may result in delayed diagnosis and associated poor health outcomes. Future research should investigate strategies that improve knowledge and screening of atypical AN in medical and other settings.

PUBLIC SIGNIFICANCE

Pediatric and Family Medicine clinicians are less familiar with atypical anorexia nervosa (AN) and less likely to diagnose a patient with atypical AN relative to AN. Insufficient knowledge about atypical AN may place these individuals at increased risk for worsening restrictive eating and the physical and psychological consequences of malnutrition.

Predictors of psychopathology response in atypical anorexia nervosa following inpatient treatment: A propensity score matching study of weight suppression and weight loss speed

INTRODUCTION

This study examines weight suppression (WS) and weight loss speed (WLS) in atypical anorexia nervosa (AN) and its implications for treatment outcomes, compared to people with AN and bulimia nervosa (BN).

METHOD

A mixed cross-sectional and prospective design was employed, assessing WS and WLS in people with atypical AN, AN, and BN. Participants were matched for age, gender, age of onset, and disorder duration. Clinical measurements and eating disorders questionnaire (EDE-Q) scores were employed to evaluate the response to treatment.

RESULTS

Individuals with atypical individuals exhibited WS patterns similar to AN, distinct from BN. Rapid WLS predicted clinical responses in atypical AN and BN, underscoring its treatment relevance. Atypical AN showed higher eating psychopathology scores than AN or BN, emphasizing the need for a reframed diagnosis.

DISCUSSION

Understanding atypical AN's connection to restrictive behaviors and weight loss informs screening, assessment, and treatment practices. Recognition of atypical AN's severity and adoption of tailored approaches are essential for recovery. This study highlights the significance of WS and WLS in atypical AN treatment outcomes, offering insights into clinical practice and care. The proposal to reframe atypical AN as a restrictive eating disorder emphasizes its clinical relevance.

PUBLIC SIGNIFICANCE STATEMENT

The phenomenon of weight suppression, involving the discrepancy between past highest weight and current weight, has garnered attention due to cultural pressures emphasizing fitness and appearance. This study focuses on its implications in atypical anorexia nervosa, aiming to uncover the relationship between WS, its speed, and treatment outcomes. The investigation contributes insights into tailored interventions for atypical anorexia nervosa and enriches the understanding of this complex disorder's dynamics.

Premorbid body weight predicts weight loss in both anorexia nervosa and atypical anorexia nervosa: Further support for a single underlying disorder

OBJECTIVE

For adolescents, DSM-5 differentiates anorexia nervosa (AN) and atypical AN with the 5th BMI-centile-for-age. We hypothesized that the diagnostic weight cut-off yields (i) lower weight loss in atypical AN and (ii) discrepant premorbid BMI distributions between the two disorders. Prior studies demonstrate that premorbid BMI predicts admission BMI and weight loss in patients with AN. We explore these relationships in atypical AN.

METHOD

Based on admission BMI-centile < or ≥5th, participants included 411 female adolescent inpatients with AN and 49 with atypical AN from our registry study. Regression analysis and t-tests statistically addressed our hypotheses and exploratory correlation analyses compared interrelationships between weight loss, admission BMI, and premorbid BMI in both disorders.

RESULTS

Weight loss in atypical AN was 5.6 kg lower than in AN upon adjustment for admission age, admission height, premorbid weight and duration of illness. Premorbid BMI-standard deviation scores differed by almost one between both disorders. Premorbid BMI and weight loss were strongly correlated in both AN and atypical AN.

DISCUSSION

Whereas the weight cut-off induces discrepancies in premorbid weight and adjusted weight loss, AN and atypical AN overall share strong weight-specific interrelationships that merit etiological consideration. Epidemiological and genetic associations between AN and low body weight may reflect a skewed premorbid BMI distribution. In combination with prior findings for similar psychological and medical characteristics in AN and atypical AN, our findings support a homogenous illness conceptualization. We propose that diagnostic subcategorization based on premorbid BMI, rather than admission BMI, may improve clinical validity.

PUBLIC SIGNIFICANCE

Because body weights of patients with AN must drop below the 5th BMI-centile per DSM-5, they will inherently require greater weight loss than their counterparts with atypical AN of the same sex, age, height and premorbid weight. Indeed, patients with atypical AN had a 5.6 kg lower weight loss after controlling for these variables. In comparison to the reference population, we found a lower and higher mean premorbid weight in patients with AN and atypical AN, respectively. Considering previous psychological and medical comparisons showing little differences between AN and atypical AN, we view a single disorder as the most parsimonious explanation. Etiological models need to particularly account for the strong relationship between weight loss and premorbid body weight.

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.

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.

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.

Lower region-specific gray matter volume in females with atypical anorexia nervosa and anorexia nervosa

OBJECTIVE

Few studies have focused on brain structure in atypical anorexia nervosa (atypical AN). This study investigates differences in gray matter volume (GMV) between females with anorexia nervosa (AN) and atypical AN, and healthy controls (HC).

METHOD

Structural magnetic resonance imaging data were acquired for 37 AN, 23 atypical AN, and 41 HC female participants. Freesurfer was used to extract GMV, cortical thickness, and surface area for six brain lobes and associated cortical regions of interest (ROI). Primary analyses employed linear mixed-effects models to compare group differences in lobar GMV, followed by secondary analyses on ROIs within significant lobes. We also explored relationships between cortical gray matter and both body mass index (BMI) and symptom severity.

RESULTS

Our primary analyses revealed significant lower GMV in frontal, temporal and parietal areas (FDR < .05) in AN and atypical AN when compared to HC. Lobar GMV comparisons were non-significant between atypical AN and AN. The parietal lobe exhibited the greatest proportion of affected cortical ROIs in both AN versus HC and atypical AN versus HC. BMI, but not symptom severity, was found to be associated with cortical GMV in the parietal, frontal, temporal, and cingulate lobes. No significant differences were observed in cortical thickness or surface area.

DISCUSSION

We observed lower GMV in frontal, temporal, and parietal areas, when compared to HC, but no differences between AN and atypical AN. This indicates potentially overlapping structural phenotypes between these disorders and evidence of brain changes among those who are not below the clinical underweight threshold.

PUBLIC SIGNIFICANCE

Despite individuals with atypical anorexia nervosa presenting above the clinical weight threshold, lower cortical gray matter volume was observed in partial, temporal, and frontal cortices, compared to healthy individuals. No significant differences were found in cortical gray matter volume between anorexia nervosa and atypical anorexia nervosa. This underscores the importance of continuing to assess and target weight gain in clinical care, even for those who are presenting above the low-weight clinical criteria.

Differentiation between atypical anorexia nervosa and anorexia nervosa using machine learning

OBJECTIVE

Body mass index (BMI) is the primary criterion differentiating anorexia nervosa (AN) and atypical anorexia nervosa despite prior literature indicating few differences between disorders. Machine learning (ML) classification provides us an efficient means of accurately distinguishing between two meaningful classes given any number of features. The aim of the present study was to determine if ML algorithms can accurately distinguish AN and atypical AN given an ensemble of features excluding BMI, and if not, if the inclusion of BMI enables ML to accurately classify between the two.

METHODS

Using an aggregate sample from seven studies consisting of individuals with AN and atypical AN who completed baseline questionnaires (N = 448), we used logistic regression, decision tree, and random forest ML classification models each trained on two datasets, one containing demographic, eating disorder, and comorbid features without BMI, and one retaining all features and BMI.

RESULTS

Model performance for all algorithms trained with BMI as a feature was deemed acceptable (mean accuracy = 74.98%, mean area under the receiving operating characteristics curve [AUC] = 74.75%), whereas model performance diminished without BMI (mean accuracy = 59.37%, mean AUC = 59.98%).

DISCUSSION

Model performance was acceptable, but not strong, if BMI was included as a feature; no other features meaningfully improved classification. When BMI was excluded, ML algorithms performed poorly at classifying cases of AN and atypical AN when considering other demographic and clinical characteristics. Results suggest a reconceptualization of atypical AN should be considered.

PUBLIC SIGNIFICANCE

There is a growing debate about the differences between anorexia nervosa and atypical anorexia nervosa as their diagnostic differentiation relies on BMI despite being similar otherwise. We aimed to see if machine learning could distinguish between the two disorders and found accurate classification only if BMI was used as a feature. This finding calls into question the need to differentiate between the two disorders.

Eating behavior in atypical anorexia nervosa

OBJECTIVE

Atypical anorexia nervosa (AN) has been increasingly identified in the community and in clinical settings. Initial studies indicate that psychological symptoms are similar or more severe among patients with atypical AN, as compared with AN. This study examined whether eating behavior differed among patients with AN (n = 98), patients with atypical AN (n = 18), and healthy controls (HC, n = 75).

METHOD

Adults and adolescents chose what to eat from a standardized, laboratory-based multi-item meal. Total intake, macronutrient composition, diet variety, and energy density were compared between groups.

RESULTS

Both AN and atypical AN severely restricted caloric intake as compared with HC (431 ± 396 kcal and 340 ± 338 kcal vs. 879 ± 350 kcal, F2,188 = 35.4, p < .001). Individuals with AN and atypical AN did not differ in the mean intake of total calories or percentage of calories from fat (15.2 ± 25.2% vs. 11.5 ± 16.9%).

DISCUSSION

This study demonstrates that individuals with atypical AN are at least as restrictive in their food intake as individuals with AN, and the restriction of dietary fat is particularly notable. Examination of eating behavior in a larger sample would be useful to replicate these findings. The current study highlights the need to understand maladaptive eating behavior in atypical AN in order to develop appropriate treatment recommendations.

PUBLIC SIGNIFICANCE

Atypical anorexia nervosa is emerging as a prevalent eating disorder in community and clinical populations. The findings that patients with atypical anorexia nervosa limit calorie and fat intake in a pattern similar to that of patients with anorexia nervosa highlights the need for research to identify appropriate treatment strategies for normalization of eating patterns.

Naturalistic symptom trajectories of atypical anorexia nervosa, anorexia nervosa, and bulimia nervosa in a prospective cohort study of United States college students

OBJECTIVE

Research on the natural course of symptoms of atypical anorexia nervosa (AN) relative to AN and bulimia nervosa (BN) is limited yet needed to inform nosology and improve understanding of atypical AN. This study aimed to 1) characterize trajectories of eating disorder and internalizing (anxiety, depression) symptoms in college students with and without a history of atypical AN, AN, and BN; and 2) compare sex and race/ethnicity distributions across groups.

METHOD

United States college students who participated in Spit for Science™, a prospective cohort study, were classified as having a history of atypical AN (n = 125), AN (n = 160), BN (n = 617), or as non-eating-disorder controls (NCs, n = 5876). Generalized and linear mixed-effects models assessed group differences in eating and internalizing symptom trajectories, and logistic regression compared groups on sex and race/ethnicity distributions.

RESULTS

Atypical AN participants demonstrated elevated eating disorder and internalizing symptoms compared to NCs during college, but less severe symptoms than AN and BN participants. Although all eating disorder groups showed signs of improvement in fasting and driven exercise, purging and depression remained elevated. Atypical AN participants showed increasing anxiety and stable binge-eating trajectories compared to AN and/or BN participants. The atypical AN group comprised significantly more people of color than the AN group.

DISCUSSION

Findings underscore that atypical AN is a severe psychiatric disorder. As atypical AN may present as less severe than AN and BN and disproportionately affects people of color, clinicians should be mindful of biases that could delay diagnosis and care.

PUBLIC SIGNIFICANCE

College students with histories of atypical AN, AN, and BN demonstrated improvements in fasting and driven exercise and stable purging and depression levels. Atypical AN students showed worsening anxiety and stable binge-eating trajectories compared to favorable changes among AN and BN students. A higher percentage of atypical AN (vs. AN) students were people of color. Findings may improve the detection of atypical AN in college students.

Time to revisit the definition of atypical anorexia nervosa

In this special issue, international researchers investigate how atypical anorexia nervosa (atypical AN) differs from anorexia nervosa (AN) and other eating disorders with respect to demographics, psychological and physiological morbidity, as well as treatment course and outcome. Manuscripts in this special issue report that atypical AN is associated with substantial medical and psychological morbidity, and the majority of studies find few differences between atypical AN and AN. While much remains to be learned about the long-term course and treatment response of individuals with atypical AN to psychological and pharmacological interventions, the evidence supports conceptualization of atypical AN as part of a spectrum-based restrictive eating disorder. These findings together with the potentially stigmatizing use of the term "atypical" suggest it may be time to revise the existing definition of atypical AN.

Associations between low body weight, weight loss, and medical instability in adults with eating disorders

OBJECTIVE

The physical complications of atypical anorexia nervosa remain understudied, with most studies completed in adolescents. This study seeks to examine the impact of various weight measures as predictors of medical instability in a large cohort of adult eating disorder patients.

METHODS

In this retrospective cohort study, the impact of admission body mass index (BMI), weight suppression, and recent weight loss (the rate of weight loss within the last 12 months) toward the development of medical complications of malnutrition were examined. Multivariable logistic regression assessed the association of binary clinical outcomes of interest with recent weight loss and weight suppression (adjusting for age, admission BMI, gender, and purging behaviors). Odds ratios (OR) and 99% confidence intervals were reported.

RESULTS

Greater recent weight loss increased the odds of developing low prealbumin and reduced hand grip strength. A greater weight suppression was associated with increased likelihood of amenorrhea, reduced systolic blood pressure, nadir hemoglobin, and weekly weight gain upon nutritional rehabilitation. Lower admission BMI was predictive of all the medical outcomes examined, with the exception of bradycardia, and was generally the strongest predictor based on standardized coefficients.

DISCUSSION

Recent weight loss and weight suppression are predictive of some of the physiologic changes of malnutrition, although low BMI is seemingly the greatest predictor for the development of these complications. These findings suggest that some patients with aggressive weight suppression and/or acute weight loss would benefit from medical stabilization, although this needs to be further defined.

PUBLIC SIGNIFICANCE

In adults, low BMI seems to be a better predictor of medical complications than weight suppression or aggressive recent weight loss. In adults, greater weight suppression is associated with increased likelihood of amenorrhea, reduced systolic blood pressure, nadir hemoglobin, and weight gain upon nutritional rehabilitation.

[New aspects in etiology and treatment of adolescent anorexia nervosa-a postulated bio-psycho-social model and the impact of the COVID-19 pandemic]

Anorexia nervosa is one of the most frequent chronic disorders of adolescence associated with a high mortality. During the COVID-19-pandemic, the number of hospitalized children and adolescents with anorexia nervosa significantly increased. This article outlines new research findings to decode the etiology of this serious disorder, especially a genetic disposition and changes of metabolism. Against the background of increasing rates during the COVID-19 pandemic, the importance of the gene-environment interaction is discussed, and new treatment forms are described. Besides the development of new biological treatment strategies, there is also some important progress in psychotherapeutic interventions. Carers should always be integrated when treating children and adolescents with anorexia nervosa, which is especially emphasized in the new "home treatment" setting. The new concept of anorexia nervosa as a metabo-psychiatric disorder gives us hope for new research ideas and treatment strategies in this often-debilitating disorder of childhood and adolescence.

Deficits in volumetric bone mineral density, bone microarchitecture, and estimated bone strength in women with atypical anorexia nervosa compared to healthy controls

OBJECTIVE

Anorexia nervosa is associated with low bone mineral density (BMD) and deficits in bone microarchitecture and strength. Low BMD is common in atypical anorexia nervosa, in which criteria for anorexia nervosa are met except for low weight. We investigated whether women with atypical anorexia nervosa have deficits in bone microarchitecture and estimated strength at the peripheral skeleton.

METHOD

Measures of BMD and microarchitecture were obtained in 28 women with atypical anorexia nervosa and 27 controls, aged 21-46 years.

RESULTS

Mean tibial volumetric BMD, cortical thickness, and failure load were lower, and radial trabecular number and separation impaired, in atypical anorexia nervosa versus controls (p < .05). Adjusting for weight, deficits in tibial cortical bone variables persisted (p < .05). Women with atypical anorexia nervosa and amenorrhea had lower volumetric BMD and deficits in microarchitecture and failure load versus those with eumenorrhea and controls. Those with a history of overweight/obesity or fracture had deficits in bone microarchitecture versus controls. Tibial deficits were particularly marked. Less lean mass and longer disease duration were associated with deficits in high-resolution peripheral quantitative computed tomography (HR-pQCT) variables in atypical anorexia nervosa.

DISCUSSION

Women with atypical anorexia nervosa have lower volumetric BMD and deficits in bone microarchitecture and strength at the peripheral skeleton versus controls, independent of weight, and particularly at the tibia. Women with atypical anorexia nervosa and amenorrhea, less lean mass, longer disease duration, history of overweight/obesity, or fracture history may be at higher risk. This is salient as deficits in HR-pQCT variables are associated with increased fracture risk.

PUBLIC SIGNIFICANCE

Atypical anorexia nervosa is a psychiatric disorder in which psychological criteria for anorexia nervosa are met despite weight being in the normal range. We demonstrate that despite weight in the normal range, women with atypical anorexia nervosa have impaired bone density, structure, and strength compared to healthy controls. Whether this translates to an increased risk of incident fracture in this population requires further investigation.

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.

Clinical characteristics of hospitalized male adolescents and young adults with atypical anorexia nervosa

OBJECTIVE

To describe the clinical characteristics of male adolescents and young adults hospitalized for medical complications of atypical anorexia nervosa (atypical AN) and to compare their clinical characteristics with females with atypical AN and males with anorexia nervosa (AN).

METHOD

A retrospective review of electronic medical records for patients with atypical AN and AN aged 9-25 admitted to the UCSF Eating Disorders Program from May 2012 to August 2020 was conducted.

RESULTS

Among 21 males with atypical AN (mean age 15.1 ± 2.7, mean %mBMI 102.0 ± 11.8), medical complications evidenced by admission laboratory values included anemia (52.9%), vitamin D insufficiency/deficiency (52.6%), and zinc deficiency (31.6%). Compared with females with atypical AN (n = 69), males with atypical AN had longer length of stay (11.4 vs 8.4 days, p = .004), higher prescribed kcal at discharge (4114 vs 3045 kcal, p < .001), lower heart rate nadir (40.0 vs 45.8, p = .038), higher aspartate transaminase (AST, 37.9 vs 26.2 U/L, p = .032), higher alanine transaminase (ALT, 30.6 vs 18.3 U/L, p = .005), and higher rates of anemia (52.9% vs 19.4%, p = .005), with no differences in vitamin D, zinc, and vital signs. Compared with males with AN (n = 40), males with atypical AN had no significant differences in vital signs or laboratory assessments during the hospitalization.

DISCUSSION

Atypical AN in males leads to significant medical comorbidity, and males with atypical AN require longer hospital stays compared to females with atypical AN. Rates of abnormal vital signs and abnormal serum laboratory values during hospital admissions do not differ in males with atypical AN compared to AN.

PUBLIC SIGNIFICANCE

Adolescent and young adult males with atypical anorexia nervosa experience significant medical complications. Males with atypical anorexia nervosa had longer hospitalizations and higher prescribed nutrition at discharge than females. Medical complications of atypical anorexia nervosa in male adolescents and young adults were generally equal to those of male adolescents and young adults with anorexia nervosa. Clinicians should be aware of unique medical complications of males with atypical anorexia nervosa.

Feasibility and preliminary effectiveness of a cognitive-behavioral, family-centered partial hospitalization program for adolescents with anorexia nervosa and atypical anorexia nervosa at six- and twelve-month follow-up

This study examined the feasibility and preliminary effectiveness of a cognitive-behavioral, family-centered partial hospitalization program (PHP) for adolescents with anorexia nervosa (AN) and atypical AN (AAN), and described the outpatient services received following discharge. Participants (N = 31) completed anthropometric and self-report assessments at admission, discharge, and six and twelve months after discharge from the PHP. Descriptive statistics explored markers of feasibility. Paired samples t-tests evaluated changes in weight and eating disorder (ED) symptomatology from admission to discharge, admission to six-month follow-up, and admission to twelve-month follow-up. Descriptive statistics and effect sizes compared symptoms at each timepoint between participants with AN and AAN. Results indicated that we were successful at recruiting greater than 50% of adolescents approached for this study. We collected follow-up data from more than 70% of participants at discharge, but did not meet this retention benchmark at six-month and twelve-month follow-ups. The entire sample demonstrated significant improvements in weight and ED symptomatology from admission to discharge, and generally maintained these improvements at six- and twelve-month follow-up. While descriptive statistics suggested that participants with AN and AAN received similar outpatient services following discharge from the PHP, those with AN experienced greater improvement in self-reported ED symptomatology than those with AAN at six- and twelve-month follow-up. These findings provide preliminary support for the efficacy of PHPs in treating adolescents with AN and AAN. Further research with larger sample sizes should investigate whether adolescents with AAN experience poorer outcomes than those with AN following discharge from a PHP.

Prevalence of suicide attempt, suicide ideation and self-harm at diagnosis in adolescents with eating disorders

BACKGROUND

Data concerning the suicide prevalence of eating disorder (ED) subtypes and predictive factors are lacking in youth. This study aimed to examine suicide attempts (SA), suicide ideation (SI) and self-harm (SH) upon diagnosis in adolescents with EDs.

METHODS

The prevalence of SA, SI and SH in ED subtypes was evaluated by retrospectively assessing the Home, Education/Employment, Eating, Activities, Drugs, Sexuality, Suicidal ideation and Safety (HEEADSSS) instrument of adolescents diagnosed with an ED. Clinical predictors of SI in anorexia nervosa (AN) and atypical AN (AAN) were assessed.

RESULTS

Among all participants (398), 41 (10.3%) reported SA, 126 (31.7%) SI and 60 (15.1%) SH. While SA did not differ statistically between ED subgroups (p = .123), they were two times more prevalent in the bulimia nervosa (BN) group (17.5%) than in the AN group (8.5%). In the BN group, SI was 2.3 times more prevalent than in the AN group (p = .001). The AN and ARFID groups exhibited substantially less SH (p = .036). Having a higher body mass index (BMI) was the only significant predictor of SI.

CONCLUSIONS

This study demonstrates that adolescents with EDs are at an increased risk for suicidality, highlighting the need for close screening, particularly in those with BN, AN-BP and AN with a higher BMI.

Preliminary associations of body weight, weight bias, and dietary restriction with eating disorder diagnosis in women experiencing food insecurity

Understanding the co-occurrence of food insecurity and eating disorders is a pressing concern. Several factors have been hypothesized to increase risk for eating disorders in women with food insecurity including dietary restriction, body weight, and weight-related bias, but few studies have tested these factors simultaneously to determine which are associated most strongly with eating disorder status. We tested cross-sectional associations of dietary restriction, current body mass index (BMI), weight suppression (i.e. the difference between current weight and highest weight), and weight bias with eating disorder diagnosis in a sample of 99 self-identified women with current food insecurity (54% White; mean [SD] age = 40.26 [14.33] years). Participants completed two virtual study visits consisting of electronic questionnaires and interviews. A binary logistic regression model was conducted to test relations between the hypothesized correlates and eating disorder diagnostic status in the past 12 months, controlling for age, food insecurity severity, and body dissatisfaction. Higher levels of weight suppression and weight bias, but not current BMI, were significantly associated with the presence of an eating disorder. Contrary to our hypothesis, greater dietary restriction was associated with lower likelihood of eating disorder diagnosis. Results suggest high levels of weight bias and weight suppression characterize women with food insecurity who meet criteria for an eating disorder. Women who experience food insecurity and have lost a relatively great deal of weight and/or hold biases about high weight should be screened for eating pathology in clinical settings.

[Consenso del grupo de trabajo de los trastornos de la conducta alimentaria de SENPE (GTTCA-SENPE). Evaluación y tratamiento médico-nutricional en la anorexia nerviosa. Actualización 2023]

Anorexia nervosa (AN) is a multifactorial disorder. A possible role of the social network and the gut microbiota in pathogenesis has been added. Exogenous shocks such as the COVID19 pandemic have had a negative impact on patients with AN. The potential medical and nutritional impact of malnutrition and/or compensatory behaviors gives rise to a complex disease with a wide range of severity, the management of which requires a multidisciplinary team with a high level of subject matter expertise. Coordination between levels of care is necessary as well as understanding how to transition the patient from pediatric to adult care is essential. A proper clinical evaluation can detect possible complications, as well as establish the organic risk of the patient. This allows caregivers to tailor the medical-nutritional treatment for each patient. Reestablishing adequate nutritional behaviors is a fundamental pillar of treatment in AN. The design of a personalized nutritional treatment and education program is necessary for this purpose. Depending on the clinical severity, artificial nutrition may be necessary. Although the decision regarding the level of care necessary at diagnosis or during follow-up depends on a number of factors (awareness of the disease, medical stability, complications, suicidal risk, outpatient treatment failure, psychosocial context, etc.), outpatient treatment is the most frequent and most preferred choice. However, more intensive care (total or partial hospitalization) may be necessary in certain cases. In severely malnourished patients, the appearance of refeeding syndrome should be prevented during renourishment. The presence of AN in certain situations (pregnancy, vegetarianism, type 1 diabetes mellitus) requires specific care. Physical activity in these patients must also be addressed correctly.

The value of a multidisciplinary consensus meeting in achieving agreement on eating disorders diagnosis at a specialized referral center

OBJECTIVE

This study aimed to evaluate the concordance of eating disorders (EDs) diagnoses within a multidisciplinary team in a specialized hospital unit dedicated to the medical care of ED.

METHODS

The study analyzed data from 608 female patients who sought consultation at the Eating Disorders Referral Center between 2017 and 2021. The diagnoses were established according to the DSM-5 criteria by endocrinologists, psychiatrists, and finally confirmed or discussed within a monthly multidisciplinary consensus meeting (MCM). Fleiss' Kappa tests were conducted to assess inter-raters' agreement.

RESULTS

Overall, substantial agreement was observed between endocrinologists and psychiatrists and the MCM. A more detailed analysis revealed variations in agreement across different disorders. Certain EDs demonstrated substantial agreement (e.g., anorexia nervosa restrictive subtype), while others approached near-perfect agreement (e.g., binge-eating disorder). In contrast, agreement was fair to poor for anorexia nervosa binge-purge subtype (ANBP) and slight for other specified feeding and ED. A period of temporary disagreement was noted for ANBP, partially attributed to practitioner turnover. An improvement in interdisciplinary agreement was observed for all ED diagnoses by the end of the study period.

DISCUSSION

Variations or lower levels of inter-rater agreement may stem from atypical cases that fall on the border between two diagnoses or complex cases, as well as fluctuating symptoms. The progress observed throughout the study can be attributed in part to interdisciplinary learning, particularly facilitated by the MCM. The findings underscore the significance of striving for optimal concordance among different medical specialties to enhance patient care in ED treatment.

PUBLIC SIGNIFICANCE

This study scrutinizes the agreement levels of ED diagnoses among endocrinologists and psychiatrists within a multidisciplinary team at an Eating Disorders Referral Center. While substantial overall agreement was achieved, disparities or lower agreement levels were evident for certain diagnoses such as anorexia nervosa binge-purge subtype. However, collaborative meetings led to a progressive enhancement in agreement over time. This research underscores the crucial role of a multidisciplinary team working collectively to ensure precise diagnoses and improved care for patients with EDs.

Strategies for Creating Multidisciplinary Community Care Teams to Address Barriers to Providing Family Based Treatment of Eating Disorders

Eating disorders, especially anorexia nervosa, are complex and devastating illnesses. Although eating disorders have a high mortality rate and are relatively common, there are many barriers for those seeking treatment. Provider training and education, weight bias among health care providers, geographical and language barriers, and a lack of options because of insurance restrictions prevent many families from receiving appropriate care, especially in smaller or rural communities. In those areas, providers are left to piece together treatment using a small number of other providers from different disciplines who have a willingness to work with this population. Outpatient family based treatment is an evidenced-based treatment of anorexia nervosa and relies on a multidisciplinary approach to care. Community-based care teams can be an effective way to treat those with eating disorders seeking family based treatment. There are several strategies for building collaborative teams that can provide comprehensive and accessible care to those with few options. [Pediatr Ann. 2024;53(1):e22-e27.].

Renal failure following insulin purging in atypical anorexia nervosa and type 1 diabetes mellitus

Objective

Anorexia nervosa (AN) and atypical anorexia nervosa (AAN) are severe and complex eating disorders that can be prevalent among individuals with type 1 diabetes mellitus (T1DM). Insulin purging, characterized by the intentional underuse / omission of insulin to control weight, is under-recognized in medicine and is a purging strategy of patients with AN or AAN and comorbid T1DM. Often, this can lead to renal failure, necessitating a (pancreas-) kidney transplantation. This article presents a comprehensive overview of the interplay between AN/AAN and T1DM and summarizes the evidence in literature.

Methods

A narrative review is presented on basis of a detailed case study of a 32-year-old female with end-stage renal failure seeking (pancreas-) kidney transplantation displaying etiology, diagnosis, comorbidities, complications, and treatment of AN and AAN with emphasis on those patients with T1DM.

Results

Insulin purging in patients with AN/AAN and coexisting T1DM can exacerbate T1DM complications, including accelerating the onset of end-stage renal failure. A multidisciplinary approach including nutrition treatment and psychotherapeutic techniques was considered necessary for treatment, focusing on psychosomatic in-patient care before and after organ transplantation.

Conclusion

Insulin purging in patients with AAN and T1DM poses severe health risks, including accelerated renal complications. For those considering transplantation, insulin purging has explicitly to be diagnosed and a holistic treatment addressing both the renal condition and psychosomatic symptoms/disorders is crucial for successful post-transplant outcomes.

Triggers for eating disorder onset in youth with anorexia nervosa across the weight spectrum

To aid in more targeted eating disorder (ED) prevention efforts, we sought to identify sociodemographic and weight-related risk factors for identified triggers for the onset of anorexia nervosa (AN) in youth. We conducted a retrospective chart review of youth admitted for medical treatment of AN between January 2015 and February 2020. From multidisciplinary admission notes, we extracted patient-reported reasons for diet/exercise changes. We used qualitative thematic analysis to identify ED triggers, then categorized each trigger as binary variables (presence/absence) for logistic regression analysis of risks associated with each trigger. Of 150 patients, mean (SD) age was 14.1(2.3) years. A total of 129 (86%) were female and 120 (80%) were Non-Hispanic White. Triggers included environmental stressors (reported by 30%), external pressures of the thin/fit ideal (29%), internalized thin/fit ideal (29%), weight-related teasing (19%), and receiving health education (14%). Younger age was associated with higher odds of weight-related teasing (p = .04) and health education (p = .03). Males had greater odds of internalized thin/fit ideal than females (p = .04). Those with premorbid body mass indices ≥85th percentile for age and sex had greater odds of reporting positive reinforcement (p = .03) and weight-related teasing (p = .04) than those with weights <85th percentile. We use these findings to detail potential targets for advancing ED prevention efforts.

Case report: clinical improvements observed in first off-label metreleptin treatment of a patient with atypical anorexia nervosa

Off-label metreleptin treatment resulted in cognitive, emotional and behavioral improvements of patients with anorexia nervosa, who presented with hypoleptinemia. We now report a case study of a 16-year-old female patient with atypical anorexia nervosa who was treated off-label with metreleptin for 11 days. She had lost 21 kg over 6 months. Her body mass index at referral for inpatient treatment was 20 kg/m2, her serum leptin level was just within the normal range (2.4 ng/ml). Dosing resulted in prominent improvements of mood and weight phobia entailing a comparatively brief inpatient treatment. The observed improvements are similar to those observed in patients with AN, suggesting overlapping mechanisms with respect to clinical effects induced by elevations of absolute or relative hypoleptinemia. Randomized controlled trials are warranted for both eating disorders.

Anorexia nervosa and the COVID-19 pandemic among young people: a scoping review

BACKGROUND

The extent to which the recent global COVID-19 Pandemic has impacted young people with restrictive eating disorders [i.e., anorexia nervosa (AN) and atypical anorexia nervosa (AAN)] is unclear. We conducted a scoping review of the literature to identify how the pandemic has impacted this population and to identify gaps in the current literature to inform future research efforts.

MAIN BODY

We searched PubMed, EMBASE, the Web of Science, The Cochrane Library, PsycInfo, ProQuest Dissertations and Theses Global, LitCovid, Google Scholar, and relevant agency websites from 2019 to 2022. We included studies that focused on young people with AN/AAN globally. Of the 916 unduplicated articles screened, 17 articles met the inclusion criteria, reporting on 17 unique studies including 4,379 individuals. Three key findings were identified. First, an increase in hospitalizations related to eating disorders was found during COVID-19 among young people with AN and AAN. Multiple studies cited increased medical instability, even though the overall duration of disease was shorter compared to pre-pandemic levels. Second, changes in eating disorder-related symptomology during the pandemic were reported in this population, as well as poorer overall behavioral and mental health. Suggested reasons behind changes included boredom or minimal distraction from pathological thoughts, increased social isolation, increased social media and online use (e.g., reading blogs or watching YouTube), gym and school closures, changes in routines due to lockdowns and quarantines, and worries over gaining the "Quarantine 15". Third, there was an increase in the use of telemedicine as a treatment modality for the treatment of AN. Challenges were reported by both clinicians and patients regardless of past experience using telemedicine. When compared to no treatment, telemedicine was recognized as the best option during COVID-19 lockdowns; however some individuals expressed the preference for in-person treatment and planned to return to it once it became available.

CONCLUSION

The pandemic significantly impacted young people with restrictive eating disorders as seen by increased hospitalizations and requests for outpatient care. A primary driver of the changes in eating disorder symptomatology may be lockdowns and quarantines. Further research investigating how the series of lockdowns and re-openings impacted individuals with AN/AAN is warranted.

Perspectives on relapse prevention following intensive treatment of anorexia nervosa: A focus group study

OBJECTIVE

Including the perspectives of individuals with lived experience of mental health issues is a critical step in research and treatment development. Focus groups with patients with a history of treatment for anorexia nervosa (AN) were conducted in anticipation of a clinical trial of Relapse Prevention and Changing Habits (REACH+).

METHODS

Seven female adults (23-51 years) who had previously received inpatient treatment for AN, now in remission, participated in one of two semistructured focus groups. Rapid qualitative analysis was used to examine participants' contributions and identify common topics.

RESULTS

Transcript analysis yielded three topics related to relapse prevention: (1) recovery aids, including a sense of agency in treatment decisions and finding new interests/passions, (2) recovery hindrances, such as lack of access to care, and (3) identification of members of support system. Aspects of REACH+ received positive feedback, such as continuity of care from the inpatient setting and the use of telehealth. Viewpoints differed with respect to the helpfulness of obtaining patient weights in treatment. The REACH+ online platform received positive comments regarding content and usability, as well as suggestions for additional content.

DISCUSSION

Qualitative feedback from patients with a history of AN highlighted the value of engaging patients in their own treatment decisions, as well as in treatment design and innovation. Within this small group, there were differences of opinion about treatment components, specifically weight assessment, that suggest the need for further data. User-centered design provides opportunities to improve the acceptability and, therefore, dissemination of novel treatments.

PUBLIC SIGNIFICANCE

Relapse prevention is a critical treatment need for patients with anorexia nervosa, as this illness too often follows a protracted course. There are challenges in both obtaining specialized care and in retaining patients in treatment. Here, patient perspectives on these challenges offer input to allow for optimization of relapse prevention treatment. Shared decision-making may be particularly valuable to support an individual's sense of agency and engagement in care.

Neural activation of regions involved in food reward and cognitive control in young females with anorexia nervosa and atypical anorexia nervosa versus healthy controls

Anorexia nervosa (AN) and atypical AN (AtypAN) are complex neurobiological illnesses that typically onset in adolescence with an often treatment-refractory and chronic illness trajectory. Aberrant eating behaviors in this population have been linked to abnormalities in food reward and cognitive control, but prior studies have not examined respective contributions of clinical characteristics and metabolic state. Research is needed to identify specific disruptions and inform novel intervention targets to improve outcomes. Fifty-nine females with AN (n = 34) or AtypAN (n = 25), ages 10-22 years, all ≤90% expected body weight, and 34 age-matched healthy controls (HC) completed a well-established neuroimaging food cue paradigm fasting and after a standardized meal, and we used ANCOVA models to investigate main and interaction effects of Group and Appetitive State on blood oxygenation level-dependent (BOLD) activation for the contrast of exposure to high-calorie food images minus objects. We found main effects of Group with greater BOLD activation in the dorsal anterior cingulate cortex (dACC), dorsolateral prefrontal cortex (DLPFC), hippocampus, caudate, and putamen for AN/AtypAN versus HC groups, and in the three-group model including AN, AtypAN, and HC (sub-)groups, where differences were primarily driven by greater activation in the AtypAN subgroup versus HC group. We found a main effect of Appetitive State with increased premeal BOLD activation in the hypothalamus, amygdala, nucleus accumbens, and caudate for models that included AN/AtypAN and HC groups, and in BOLD activation in the nucleus accumbens for the model that included AN, AtypAN, and HC (sub-)groups. There were no interaction effects of Group with Appetitive State for any of the models. Our findings demonstrate robust feeding-state independent group effects reflecting greater neural activation of specific regions typically associated with reward and cognitive control processing across AN and AtypAN relative to healthy individuals in this food cue paradigm. Differential activation of specific brain regions in response to the passive viewing of high-calorie food images may underlie restrictive eating behavior in this clinical population.

Medical instability in typical and atypical adolescent anorexia nervosa: a systematic review and meta-analysis

This review investigates the relationship between weight and risk of medical instability (specifically bradycardia, hypotension, hypothermia, and hypophosphatemia) in adolescents with typical and atypical anorexia nervosa. Atypical anorexia nervosa, listed as an example under the DSM-5 category of Other Specified Feeding and Eating Disorders (OSFED), describes patients who are not clinically underweight but otherwise meet criteria for anorexia nervosa. There is a lack of empirical evidence exploring medical complications in adolescents presenting with atypical anorexia nervosa. The small number of studies that do exist in this area indicate that medical instability exists across a range of weights, with weight loss being associated with increased medical risk, independent of underweight. The aim of this review was to collate and analyse results from available studies and identify indicators of medical risk in these two groups of adolescents with restrictive eating disorders. Studies were identified by systematic electronic search of medical databases, including PubMed and EMBASE. All studies investigated the relationship between weight and medical instability and included adolescents diagnosed with anorexia nervosa or atypical anorexia nervosa. One randomised controlled trial, five cohort studies and three chart reviews were included, with a total sample size of 2331 participants. Between 29 and 42% of participants presented with medical instability requiring hospitalisation, in the absence of underweight. Underweight adolescents were significantly more likely to have lower blood pressures (p < 0.0001) and bradycardia was significantly associated with greater weight loss (p < 0.05). There were no statistically significant associations found between degree of underweight and heart rate, temperature, or rate of weight loss (p = 0.31, p = 0.46 and p = 0.16, respectively). Adolescents that were less than 70% median body mass index were significantly more likely to have hypophosphatemia (p < 0.05). The findings of this review support the hypothesis that medical instability can occur across a range of weights in adolescent eating disorders, with rapid weight loss being an important indicator of increasing medical risk. Results were limited by the small number of existing studies that contained data for statistical analysis. Rapid weight loss should be considered as an important indicator of medical instability in adolescents presenting with both typical and atypical anorexia nervosa.