The validity and utility of subtyping bulimia nervosa

Disentangling the links between gastric emptying and binge eating v. purging in eating disorders using a case-control design

BACKGROUND

Prior work supports delayed gastric emptying in anorexia nervosa and bulimia nervosa (BN) but not binge-eating disorder, suggesting that neither low body weight nor binge eating fully accounts for slowed gastric motility. Specifying a link between delayed gastric emptying and self-induced vomiting could offer new insights into the pathophysiology of purging disorder (PD).

METHODS

Women (N = 95) recruited from the community meeting criteria for DSM-5 BN who purged (n = 26), BN with nonpurging compensatory behaviors (n = 18), PD (n = 25), or healthy control women (n = 26) completed assessments of gastric emptying, gut peptides, and subjective responses over the course of a standardized test meal under two conditions administered in a double-blind, crossover sequence: placebo and 10 mg of metoclopramide.

RESULTS

Delayed gastric emptying was associated with purging with no main or moderating effects of binge eating in the placebo condition. Medication eliminated group differences in gastric emptying but did not alter group differences in reported gastrointestinal distress. Exploratory analyses revealed that medication caused increased postprandial PYY release, which predicted elevated gastrointestinal distress.

CONCLUSIONS

Delayed gastric emptying demonstrates a specific association with purging behaviors. However, correcting disruptions in gastric emptying may exacerbate disruptions in gut peptide responses specifically linked to the presence of purging after normal amounts of food.

Classification of subtypes of patients with eating disorders by correspondence analysis

BACKGROUND

Grouping eating disorders (ED) patients into subtypes could help improve the establishment of more effective diagnostic and treatment strategies.

AIM

To identify clinically meaningful subgroups among subjects with ED using multiple correspondence analysis (MCA).

METHODS

A prospective cohort study was conducted of all outpatients diagnosed for an ED at an Eating Disorders Outpatient Clinic to characterize groups of patients with ED into subtypes according to sociodemographic and psychosocial impairment data, and to validate the results using several illustrative variables. In all, 176 (72.13%) patients completed five questionnaires (clinical impairment assessment, eating attitudes test-12, ED-short form health-related quality of life, metacognitions questionnaire, Penn State Worry Questionnaire) and sociodemographic data. ED patient groups were defined using MCA and cluster analysis. Results were validated using key outcomes of subtypes of ED.

RESULTS

Four ED subgroups were identified based on the sociodemographic and psychosocial impairment data.

CONCLUSION

ED patients were differentiated into well-defined outcome groups according to specific clusters of compensating behaviours.

Evaluation of the DSM-5 Severity Specifier for Bulimia Nervosa in Treatment-Seeking Youth

A new severity specifier for bulimia nervosa (BN), based on the frequency of inappropriate weight compensatory behaviours (e.g., laxative misuse, self-induced vomiting, fasting, diuretic misuse, and excessive exercise), has been added to the most recent (fifth) edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) as a means of addressing variability and heterogeneity in the severity of the disorder. While existing research provides support for the DSM-5 severity specifier for BN in adult patients, evidence for its validity and clinical utility in youth is currently lacking. To address this gap, data from 272 treatment-seeking adolescents with DSM-5 BN (94.2% female, M _age = 15.3 years, SD 1.7) were analysed to examine whether these patients, sub-grouped based on the DSM-5 severity definitions, would show meaningful differences in a broad range of clinical variables and demographic and physical characteristics. Analyses revealed that participants categorized with mild, moderate, severe, and extreme severity of BN significantly differed from each other in 15 variables regarding eating disorder pathological features and putative maintenance factors (i.e., core low self-esteem, perfectionism, social appearance anxiety, body surveillance, and mood intolerance), health-related quality of life and comorbid psychiatric (i.e., affective and anxiety) disorders (large effect sizes). Between-group differences in demographics, body mass index, or age-of-BN onset were not observed. Collectively, our findings provide support for the utility of the frequency of inappropriate weight compensatory behaviours as a severity indicator for BN and suggest that age-at-onset of BN is probably more disorder- than severity-dependent. Implications for future research are outlined.

Application of structural equation mixture modeling to characterize the latent structure of eating pathology

OBJECTIVE

Several theoretical models describe the structure of eating disorders (EDs), and a burgeoning empirical literature has sought to identify whether eating pathology is conceptualized best as categorical (presence or absence of disorder), dimensional (continuous), or a hybrid of categories and dimensions.

METHODS

This study used structural equation mixture modeling (SEMM) to identify the latent structure of EDs. Items from the Eating Pathology Symptoms Inventory (EPSI) were administered to individuals with EDs (N = 344). Select EPSI scales and body mass index were indicators in subsequent SEMM analyses. The Inventory of Depression and Anxiety Symptoms (IDAS), ED diagnoses, and select demographic variables were used as validators using chi-square or MANOVA.

RESULTS

Categorical models fit the data better than latent dimensional or hybrid models. Latent profile 1 (LP1) was non-fat-phobic restricting anorexia nervosa; LP2, an obese, binge-eating class; LP3, non-purging bulimia nervosa; LP4, fat-phobic restricting anorexia nervosa; and LP5, multiple purging bulimia nervosa. External validation analyses indicated that LP4 and LP5 had the highest non-ED-related psychopathology.

DISCUSSION

These findings indicate that there is substantial variability in the phenomenology of traditional DSM-based ED categories across latent profiles, and highlight the salience of certain ED phenotypes that have been debated in the literature. © 2016 Wiley Periodicals, Inc.(Int J Eat Disord 2017; 50:542-550).

Testing the DSM-5 severity indicator for bulimia nervosa in a treatment-seeking sample

PURPOSE

This study tested the new DSM-5 severity criterion for bulimia nervosa (BN) based on the frequency of inappropriate weight compensatory behaviors in a treatment-seeking sample.

METHODS

Participants were 345 adults with DSM-5 BN presenting for treatment. They were sub-grouped based on DSM-5 severity levels and compared on a range of variables of clinical interest and demographics.

RESULTS

Based on DSM-5 severity definitions, 27.2 % of the sample was categorized with mild, 26.1 % with moderate, 24.9 % with severe, and 21.8 % with extreme severity of BN. Analyses revealed that the four (mild, moderate, severe, and extreme) severity groups of BN significantly differed from each other in eating disordered and body-related attitudes and behaviors, factors involved in the maintenance process of the disorder, comorbid psychiatric disorders, psychological distress, and psychosocial impairment (medium-to-large effect sizes). No significant between-group differences were observed in demographics, body mass index, or at the age when BN first occurred, lending some credence to recent suggestions that age-at-onset of BN may be more a disorder- than a severity-dependent variable.

CONCLUSIONS

Collectively, our findings provide support for the severity indicator for BN introduced in the DSM-5 as a means of addressing heterogeneity and variability in the severity of the disorder.

Eating disorders

Twenty years have passed from the International Classification of Diseases, Tenth Revision (ICD-10) to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) and, in the meanwhile, a lot of research data about eating disorders has been published. This article reviews the main modifications to the classification of eating disorders reported in the "Feeding and Eating Disorders" chapter of the DSM-5, and compares them with the ICD-10 diagnostic guidelines. Particularly, we will show that DSM-5 criteria widened the diagnoses of anorexia and bulimia nervosa to less severe forms (so decreasing the frequency of Eating Disorders, Not Otherwise Specified (EDNOS) diagnoses), introduced the new category of Binge Eating Disorder, and incorporated several feeding disorders that were first diagnosed in infancy, childhood, or adolescence. On the whole, the DSM-5 revision should allow the clinician to make more reliable and timely diagnoses for eating disorders.

Testing the cognitive-behavioural maintenance models across DSM-5 bulimic-type eating disorder diagnostic groups: a multi-centre study

The original cognitive-behavioural (CB) model of bulimia nervosa, which provided the basis for the widely used CB therapy, proposed that specific dysfunctional cognitions and behaviours maintain the disorder. However, amongst treatment completers, only 40-50 % have a full and lasting response. The enhanced CB model (CB-E), upon which the enhanced version of the CB treatment was based, extended the original approach by including four additional maintenance factors. This study evaluated and compared both CB models in a large clinical treatment seeking sample (N = 679), applying both DSM-IV and DSM-5 criteria for bulimic-type eating disorders. Application of the DSM-5 criteria reduced the number of cases of DSM-IV bulimic-type eating disorders not otherwise specified to 29.6 %. Structural equation modelling analysis indicated that (a) although both models provided a good fit to the data, the CB-E model accounted for a greater proportion of variance in eating-disordered behaviours than the original one, (b) interpersonal problems, clinical perfectionism and low self-esteem were indirectly associated with dietary restraint through over-evaluation of shape and weight, (c) interpersonal problems and mood intolerance were directly linked to binge eating, whereas restraint only indirectly affected binge eating through mood intolerance, suggesting that factors other than restraint may play a more critical role in the maintenance of binge eating. In terms of strength of the associations, differences across DSM-5 bulimic-type eating disorder diagnostic groups were not observed. The results are discussed with reference to theory and research, including neurobiological findings and recent hypotheses.

Integrating fundamental concepts of obesity and eating disorders: implications for the obesity epidemic

Physiological mechanisms promote weight gain after famine. Because eating disorders, obesity, and dieting limit food intake, they are famine-like experiences. The development of the concept of meeting an ideal weight was the beginning of increasing obesity. Weight stigma, the perception of being fat, lack of understanding of normal growth and development, and increased concern about obesity on the part of health providers, parents, and caregivers have reinforced each other to promote dieting. Because weight suppression and disinhibition provoke long-term weight increase, dieting is a major factor producing the obesity epidemic. The integrated eating disorder-obesity theory included in this article emphasizes that, contrary to dieters, lifetime weight maintainers depend on physiological processes to control weight and experience minimal weight change.

Risk factors across the eating disorders

This study sought to examine risk and onset patterns in anorexia nervosa (AN), bulimia nervosa (BN), and binge eating disorder (BED). Women with AN (n=71), BN (n=66), BED (n=160) and non-psychiatric controls (n=323) were compared retrospectively on risk factors, symptom onset, and diagnostic migration. Eating disorder groups reported greater risk exposure than non-psychiatric controls. AN and BED differed on premorbid personality/behavioral problems, childhood obesity, and family overeating. Risk factors for BN were shared with AN and BED. Dieting was the most common onset symptom in AN, whereas binge eating was most common in BN and BED. Migration between AN and BED was rare, but more frequent between AN and BN and between BN and BED. AN and BED have distinct risk factors and onset patterns, while BN shares similar risk factors and onset patterns with both AN and BED. Results should inform future classification schemes and prevention programs.

[Changes to the classification of Eating Disorders in DSM-5]

The fifth revision of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) resulted in substantial changes with regard to the classification of Eating Disorders. In DSM-5, Feeding and Eating Disorders are for the first time subsumed in a single category. The Binge Eating Disorder (BED) was established as the third classical eating disorder in addition to Anorexia Nervosa (AN) and Bulimia Nervosa (BN). The criteria for AN changed remarkably, whereas there were only minor changes to the BN criteria. The criteria for BED differ only marginally from the DSM-IV research criteria. There are now subtypes of AN, BN, and BED in the new category "Other Specific Feeding and Eating Disorders." The rest category "Eating Disorders Not Otherwise Specified" has been renamed to "Unspecified Feeding or Eating Disorders." The practicability of the DSM-5 criteria for Eating Disorders, and for AN in particular, for both clinical practice and research remains to be seen.

Bulimia nervosa-nonpurging subtype: closer to the bulimia nervosa-purging subtype or to binge eating disorder?

OBJECTIVE

DSM-5 has dropped subtyping of bulimia nervosa (BN), opting to continue inclusion of the somewhat contentious diagnosis of BN-nonpurging subtype (BN-NP) within a broad BN category. Some contend however that BN-NP is more like binge eating disorder (BED) than BN-P. This study examines clinical characteristics, eating disorder symptomatology, and Axis I comorbidity in BN-NP, BN-P, and BED groups to establish whether BN-NP more closely resembles BN-P or BED.

METHOD

Women with BN-P (n = 29), BN-NP (n = 29), and BED (n = 54) were assessed at baseline in an outpatient psychotherapy trial for those with binge eating. Measures included the Structured Clinical Interviews for DSM-IV, Eating Disorder Examination, and Eating Disorder Inventory-2.

RESULTS

The BN-NP subtype had BMIs between those with BN-P and BED. Both BN subtypes had higher Restraint and Drive for Thinness scores than BED. Body Dissatisfaction was highest in BN-NP and predicted BN-NP compared to BN-P. Higher Restraint and lower BMI predicted BN-NP relative to BED. BN-NP resembled BED with higher lifetime BMIs; and weight-loss clinic than eating disorder clinic attendances relative to the BN-P subtype. Psychiatric comorbidity was comparable except for higher lifetime cannabis use disorder in the BN-NP than BN-P subtype

DISCUSSION

These results suggest that BN-NP sits between BN-P and BED however the high distress driving inappropriate compensatory behaviors in BN-P requires specialist eating disorder treatment. These results support retaining the BN-NP group within the BN category. Further research is needed to determine whether there are meaningful differences in outcome over follow-up.

Patterns of compensatory behaviors and disordered eating in college students

Abstract.

OBJECTIVE

The current study investigated rates of endorsement of eating-related compensatory behaviors within a college sample.

PARTICIPANTS

This sample included male and female students (N = 1,158).

METHODS

PARTICIPANTS completed the Eating Disorder Examination Questionnaire (EDE-Q). The study defined 3 groups of students: those who did not endorse purging behaviors, those who endorsed only exercise, and those who endorsed laxative use or vomiting. Rates of related eating disorder risk variables were compared across the 3 groups.

RESULTS

Almost half of college students reported utilizing exercise as a compensatory strategy over the past 28 days. Those reporting compensatory exercise did not differ from other community and college samples on EDE-Q subscales.

CONCLUSIONS

Findings suggest that college students report significant rates of compensatory exercise, and those who report exercise as their only compensatory behavior also report relatively low levels of eating disorder risk.

Cognitive behaviour therapy response and dropout rate across purging and nonpurging bulimia nervosa and binge eating disorder: DSM-5 implications

BACKGROUND

With the imminent publication of the new edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), there has been a growing interest in the study of the boundaries across the three bulimic spectrum syndromes [bulimia nervosa-purging type (BN-P), bulimia nervosa-non purging type (BN-NP) and binge eating disorder (BED)]. Therefore, the aims of this study were to determine differences in treatment response and dropout rates following Cognitive Behavioural Therapy (CBT) across the three bulimic-spectrum syndromes.

METHOD

The sample comprised of 454 females (87 BED, 327 BN-P and 40 BN-NP) diagnosed according to DSM-IV-TR criteria who were treated with 22 weekly outpatient sessions of group CBT therapy. Patients were assessed before and after treatment using a food and binging/purging diary and some clinical questionnaires in the field of ED. "Full remission" was defined as total absence of binging and purging (laxatives and/or vomiting) behaviors and psychological improvement for at least 4 (consecutive).

RESULTS

Full remission rate was found to be significantly higher in BED (69.5%) than in both BN-P (p < 0.005) and BN-NP (p < 0.001), which presented no significant differences between them (30.9% and 35.5%). The rate of dropout from group CBT was also higher in BED (33.7%) than in BN-P (p < 0.001) and BN-NP (p < 0.05), which were similar (15.4% and 12.8%, respectively).

CONCLUSIONS

Results suggest that purging and non-purging BN have similar treatment response and dropping out rates, whereas BED appears as a separate diagnosis with better outcome for those who complete treatment. The results support the proposed new DSM-5 classification.

Normal atrial conduction in medically treated patients with bulimia nervosa

BACKGROUND

Bulimia nervosa (BN) patients are characterized by binge eating followed by compensatory behaviors. Ingestion of emetic substances, characteristic to some BN patients, has been reported to be associated with supraventricular arrhythmias.

AIMS

To evaluate atrial electrocardiographic markers for supraventricular arrhythmias in patients with BN.

METHOD

The cohort included 31 patients with BN and sex- and age-matched controls. Twelve-lead electrocardiography was conducted on all participants under strict standards. P wave length and P wave dispersion in each patient were computed from a randomly selected beat and an averaged beat constructed from 7-12 beats, included in a 10-s ECG.

RESULTS

No statistically significant differences were found between the groups for minimal, maximal, and average P wave duration and P wave dispersion, calculated either from a random beat or averaged beats.

CONCLUSION

BN patients who are medically monitored and treated, have normal P wave parameters and P wave dispersion, and therefore do not appear to have an increased risk for developing supraventricular arrhythmias. Future research should focus on evaluating the effect of acute ingestion of emetic drugs on resting ECG of BN patients, as well as using signal averaging techniques and prolonged ECG-Holter monitoring.

Classification of bulimic-type eating disorders: from DSM-IV to DSM-5

Proposed changes to the classification of bulimic-type eating disorders in the lead up to the publication of DSM-5 are reviewed. Several of the proposed changes, including according formal diagnostic status to binge eating disorder (BED), removing the separation of bulimia nervosa (BN) into purging and non-purging subtypes, and reducing the binge frequency threshold from twice per week to once per week for both BN and (BED), have considerable empirical evidence to support them and will likely have the effect of facilitating clinical practice, improving access to care, improving public and professional awareness and understanding of these disorders and stimulating the additional research needed to address at least some problematic issues. However, the omission of any reference to variants of BN characterized by subjective, but not objective, binge eating episodes, and to the undue influence of weight or shape on self-evaluation or similar cognitive criterion in relation to the diagnosis of BED, is regrettable, given their potential to inform clinical and research practice and given that there is considerable evidence to support specific reference to these distinctions. Other aspects of the proposed criteria, such as retention of behavioral indicators of impaired control associated with binge eating and the presence of marked distress regarding binge eating among the diagnostic for BED, appear anomalous in that there is little or no evidence to support their validity or clinical utility. It is hoped that these issues will be addressed in final phase of the DSM-5 development process.

A debate on current eating disorder diagnoses in light of neurobiological findings: is it time for a spectrum model?

BACKGROUND

Sixty percent of eating disorders do not meet criteria for anorexia- or bulimia nervosa, as defined by the Diagnostic and Statistical Manual version 4 (DSM-IV). Instead they are diagnosed as 'eating disorders not otherwise specified' (EDNOS). Discrepancies between criteria and clinical reality currently hampering eating disorder diagnoses in the DSM-IV will be addressed by the forthcoming DSM-V. However, future diagnoses for eating disorders will rely on current advances in the fields of neuroimaging and genetics for classification of symptoms that will ultimately improve treatment.

DISCUSSION

Here we debate the classification issues, and discuss how brain imaging and genetic discoveries might be interwoven into a model of eating disorders to provide better classification and treatment. The debate concerns: a) current issues in the classification of eating disorders in the DSM-IV, b) changes proposed for DSM-V, c) neuroimaging eating disorder research and d) genetic eating disorder research.

SUMMARY

We outline a novel evidence-based 'impulse control' spectrum model of eating disorders. A model of eating disorders is proposed that will aid future diagnosis of symptoms, coinciding with contemporary suggestions by clinicians and the proposed changes due to be published in the DSM-V.

Classification of feeding and eating disorders: review of evidence and proposals for ICD-11

Current classification of eating disorders is failing to classify most clinical presentations; ignores continuities between child, adolescent and adult manifestations; and requires frequent changes of diagnosis to accommodate the natural course of these disorders. The classification is divorced from clinical practice, and investigators of clinical trials have felt compelled to introduce unsystematic modifications. Classification of feeding and eating disorders in ICD-11 requires substantial changes to remediate the shortcomings. We review evidence on the developmental and cross-cultural differences and continuities, course and distinctive features of feeding and eating disorders. We make the following recommendations: a) feeding and eating disorders should be merged into a single grouping with categories applicable across age groups; b) the category of anorexia nervosa should be broadened through dropping the requirement for amenorrhoea, extending the weight criterion to any significant underweight, and extending the cognitive criterion to include developmentally and culturally relevant presentations; c) a severity qualifier "with dangerously low body weight" should distinguish the severe cases of anorexia nervosa that carry the riskiest prognosis; d) bulimia nervosa should be extended to include subjective binge eating; e) binge eating disorder should be included as a specific category defined by subjective or objective binge eating in the absence of regular compensatory behaviour; f) combined eating disorder should classify subjects who sequentially or concurrently fulfil criteria for both anorexia and bulimia nervosa; g) avoidant/restrictive food intake disorder should classify restricted food intake in children or adults that is not accompanied by body weight and shape related psychopathology; h) a uniform minimum duration criterion of four weeks should apply.

Test-retest reliability of the proposed DSM-5 eating disorder diagnostic criteria

The proposed DSM-5 classification scheme for eating disorders includes both major and minor changes to the existing DSM-IV diagnostic criteria. It is not known what effect these modifications will have on the ability to make reliable diagnoses. Two studies were conducted to evaluate the short-term test-retest reliability of the proposed DSM-5 eating disorder diagnoses: anorexia nervosa, bulimia nervosa, binge eating disorder, and feeding and eating conditions not elsewhere classified. Participants completed two independent telephone interviews with research assessors (n=70 Study 1; n=55 Study 2). Fair to substantial agreements (κ=0.80 and 0.54) were observed across eating disorder diagnoses in Study 1 and Study 2, respectively. Acceptable rates of agreement were identified for the individual eating disorder diagnoses, including DSM-5 anorexia nervosa (κ's of 0.81 to 0.97), bulimia nervosa (κ=0.84), binge eating disorder (κ's of 0.75 and 0.61), and feeding and eating disorders not elsewhere classified (κ's of 0.70 and 0.46). Further, improved short-term test-retest reliability was noted when using the DSM-5, in comparison to DSM-IV, criteria for binge eating disorder. Thus, these studies found that trained interviewers can reliably diagnose eating disorders using the proposed DSM-5 criteria; however, additional data from general practice settings and community samples are needed.

Animal models of eating disorders

Feeding is a fundamental process for basic survival and is influenced by genetics and environmental stressors. Recent advances in our understanding of behavioral genetics have provided a profound insight on several components regulating eating patterns. However, our understanding of eating disorders, such as anorexia nervosa, bulimia nervosa, and binge eating, is still poor. The animal model is an essential tool in the investigation of eating behaviors and their pathological forms, yet development of an appropriate animal model for eating disorders still remains challenging due to our limited knowledge and some of the more ambiguous clinical diagnostic measures. Therefore, this review will serve to focus on the basic clinical features of eating disorders and the current advances in animal models of eating disorders.

[Diagnostic criteria for eating disorders: what will DSM-5 feature?]

The diagnostic criteria of the classic eating disorders anorexia nervosa (AN) and bulimia nervosa (BN) are characterized by both a high validity and clinical utility. However, up to 50% of patients in specialized eating disorder centers do not meet the full diagnostic criteria and are relegated to the residual diagnosis "eating disorders not otherwise specified (EDNOS)". Eating disorders are more varied and variable than the ICD-10 or DSM-IV criteria suggest. This article describes the suggested modifications of the diagnostic criteria for eating disorders for the DSM-5. The DSM-5 abstains from setting a specific numerical standard for weight for AN and reduces the required minimum frequency for BN and binge eating disorder (BED) to once a week over the last 3 months. This will likely reduce the number of cases in the EDNOS category. In addition, the DSM-5 provides brief descriptions of several conditions of potential clinical significance without providing detailed criteria in order to stimulate additional research.

Latent class analysis of eating and impulsive behavioral symptoms in Taiwanese women with bulimia nervosa

OBJECTIVE

The implications of impulsivity in its relationship with binge-eating or purging behaviors remain unclear. This study examined the patterns of eating behaviors and co-morbid impulsive behaviors in individuals with bulimia nervosa n optimally homogeneous classes using latent class analysis (LCA).

METHODS

All participants (n=180) were asked to complete a series of self-reported inventories of impulsive behaviors and other psychological measures. Information regarding the lifetime presence of symptoms of eating disorder was assessed by clinical interviews. LCA was conducted using eating disorder symptoms, impulsive behaviors, and the number of purging methods.

RESULTS

Three latent classes of bulimic women were identified. These were women who exhibited relatively higher rates of purging, symptoms of impulsive behavior, and multiple purging methods (17.8%), women who used no more than one purging method with a low occurrence of impulsive behavior (41.7%), and women who showed higher rates of purging behaviors and the use of multiple purging methods with a low rate of impulsive behavior (41.7%). The impulsive sub-group had comparable severity of eating-related measures, frequency of binge-eating, and higher levels of general psychopathology than that of the other two sub-groups.

CONCLUSION

This study provides empirical support for the existence of an impulsive subgroup with distinctive features among a non-Western group of BN patients. This study also suggests that mechanisms other than impulse dysregulation may exist for the development of binge-eating and purging behaviors in bulimia nervosa patients, or the mechanisms contributing to binge-eating and impulsive behaviors may be different.

Medical complications of bulimia nervosa and their treatments

OBJECTIVE

To present a cogent and practical review of the medical complications and their treatment in patients with bulimia nervosa.

METHOD

Thorough review of the medical literature from 1990 to current in regards to the medical complications of bulimia nervosa and the therapeutic intervention that are effective to treat them.

RESULTS

Extensive and detailed review of the medical complications of bulimia nervosa.

How do eating disorder specialist clinicians apply DSM-IV diagnostic criteria in routine clinical practice? Implications for enhancing clinical utility in DSM-5

The clinical utility of the DSM-IV eating disorder (ED) diagnostic criteria among practicing clinicians has not been formally evaluated, despite the considerable diagnostic challenges these disorders present. This study evaluated inter-rater reliability between research and clinical diagnoses, identified discrepantly rated diagnostic criteria, and evaluated ED subtype use in a naturalistic treatment setting. Seventy-six adolescent and young adult female patients consecutively admitted to a residential ED program were evaluated independently by clinicians (unstructured clinical interview) and research assessors (Structured Clinical Interview for DSM-IV). Clinicians and research assessors conferred concordant ED diagnoses in 80.3% of cases (kappa=0.70), thus highlighting the clinical utility of the extant DSM-IV diagnostic scheme in this specialty ED treatment setting. All but two discordant cases included a diagnosis of ED not otherwise specified (EDNOS). Clinicians applied ED subtypes in just 20.4% of eligible cases, and were significantly more likely to apply subtypes to major depressive disorder. Although clinical and research interviews yielded substantial reliability, EDNOS had the lowest reliability among the ED diagnoses. Moreover, infrequent subtype application on this specialty unit raises questions about the clinical utility of DSM-IV anorexia nervosa and bulimia nervosa subtypes, even in the context of clinically useful overarching categories.

Genetic findings in anorexia and bulimia nervosa

Anorexia nervosa (AN) and bulimia nervosa (BN) are complex disorders associated with disordered eating behavior. Heritability estimates derived from twin and family studies are high, so that substantial genetic influences on the etiology can be assumed for both. As the monoaminergic neurotransmitter systems are involved in eating disorders (EDs), candidate gene studies have centered on related genes; additionally, genes relevant for body weight regulation have been considered as candidates. Unfortunately, this approach has yielded very few positive results; confirmed associations or findings substantiated in meta-analyses are scant. None of these associations can be considered unequivocally validated. Systematic genome-wide approaches have been performed to identify genes with no a priori evidence for their relevance in EDs. Family-based scans revealed linkage peaks in single chromosomal regions for AN and BN. Analyses of candidate genes in one of these regions led to the identification of genetic variants associated with AN. Currently, an international consortium is conducting a genome-wide association study for AN, which will hopefully lead to the identification of the first genome-wide significant markers.