Phenotypes, endophenotypes, and genotypes in bulimia spectrum eating disorders

Multi-family therapy for bulimia nervosa in adolescence: a pilot study in a community eating disorder service

Multi-family therapy for Bulimia Nervosa (MFT-BN) was developed in response to the modest outcomes following both Family Therapy and Cognitive Behavior Therapy for adolescents with BN. BN impacts individuals and their family members with high levels of carer stress. MFT-BN targets barriers to treatment including low motivation to change, hostility and criticism, negative affect alongside emotion dysregulation and common comorbidities. MFT-BN enhances treatment, providing a community of support and acquisition of emotional regulation and interpersonal skills. The study describes the clinical characteristics of the group of participants to whom MFT-BN is offered and presents the outcomes of families who have participated in it. Prior to MFT-BN, adolescents who received it were more likely to have self-harmed and had elevated levels of eating disordered cognitions than those who did not receive MFT-BN. Following MFT-BN, parents report decreases in the negative experiences of caregiving and in their own symptoms of anxiety. Adolescents report reductions in anxiety and depression alongside improvement in emotion regulation. Improvements in symptoms of eating disorders include reductions in eating disorder cognitions and modest reductions in binge and purge symptoms after 14 weeks of treatment. Adolescents who participated in MFT-BN were less likely to drop out of outpatient treatment.

Food insecurity associated with elevated eating disorder symptoms, impairment, and eating disorder diagnoses in an American University student sample before and during the beginning of the COVID-19 pandemic

OBJECTIVE

This study tested the association between food insecurity and eating disorder (ED) pathology, including probable ED diagnosis, among two cohorts of university students before and during the beginning of the COVID-19 pandemic.

METHOD

Students (n = 579) from a large Midwestern American university completed self-report questionnaires assessing frequency of ED behaviors, ED-related impairment, and individual food insecurity as measured by the Eating Disorder Diagnostic Scale 5, Clinical Impairment Assessment, and Radimer/Cornell, respectively. Chi-square tests and MANOVA with post-hoc corrections were conducted to compare demographic characteristics, ED pathology, and probable ED diagnosis prevalence between students with and without individual food insecurity.

RESULTS

Partially supporting hypotheses, MANOVA indicated significantly greater frequency of objective binge eating, compensatory fasting, and ED-related impairment for students with food insecurity compared with individuals without food insecurity. Chi-squared tests showed higher prevalence of ED diagnoses among individuals with food insecurity compared with those without food security (47.6 vs. 31.1%, respectively, p < .01, NNT = 6.06), specifically bulimia nervosa and other specified feeding and eating disorder. There were no differences in food insecurity before or during the beginning of the COVID-19 pandemic.

DISCUSSION

Consistent with prior literature, food insecurity was associated with elevated ED psychopathology in this sample. Findings emphasize the importance of proper ED screening for college students vulnerable to food insecurity and EDs.

Impulsivity and compulsivity in anorexia and bulimia nervosa: A systematic review

This study aimed to systematically appraise cross-sectional research that compared the cognitive performance of individuals in the acute phase of BN and/or AN to HCs on measures of impulsivity and compulsivity. The results of the systematic review showed support for the trans-diagnostic approach to eating disorders. There was no strong evidence to support the characterisation of AN as high in compulsivity (and low in impulsivity), nor to support the characterisation of BN as high in impulsivity (and low in compulsivity). There appeared to be mixed findings for both impulsivity and compulsivity across AN and BN. Results were highly variable due to the heterogeneous tasks used, and lack of replication across studies. There was no consensus amongst the included studies on the most appropriate task and/or outcome measures that should be used to study the constructs of impulsivity and compulsivity.

Residual eating disorder symptoms and clinical features in remitted and recovered eating disorder patients: A systematic review with meta-analysis

OBJECTIVE

In psychiatry, the presence of residual symptoms after treatment is linked to the definitions of remission and recovery. To identify the presence of residual eating disorder (ED) symptoms and associated non-ED clinical features in remitted and recovered EDs, the current systematic review with meta-analysis was performed.

METHOD

A systematic review was conducted on residual ED symptoms and non-ED clinical features including comorbid psychopathology, neurophysiological functioning, cognitive functioning, and quality of life in ED patients considered remitted or recovered. To examine residual ED symptoms, meta-analyses were performed while considering age, study quality, remission, and recovery criteria strictness as moderators. Sensitivity, publication bias, and heterogeneity analyses were also conducted.

RESULTS

The 64 studies selected for the systematic review underscored the presence of residual ED symptoms in anorexia nervosa (AN) and bulimia nervosa (BN), and impairments and deficits in the additional features examined. From the 64 studies, 31 were selected regarding residual ED symptoms in AN for meta-analysis. Large effect sizes indicated that remitted/recovered AN patients reported significantly lower body mass index (Hedges' g = -0.62[-0.77, -0.46]) and significantly greater symptomatology in terms of ED examination-questionnaire (Hedges'g = 0.86 [0.48,1.23]) and ED inventory (Hedges' g = 0.94[0.64,1.24]) than healthy controls, independently of remission and recovery criteria strictness, age, and study quality.

DISCUSSION

The presence of residual ED symptoms in AN is quantitatively supported, whereas the presence of residual ED symptoms in BN should be further investigated. Data on binge-eating disorder are missing. Future research should use consistent, multicomponent, and standardized comparable indicators of recovery.

Personality Variables and Eating Pathology

Personality variables have long been implicated in the onset and maintenance of eating disorders, as well as in symptom divergence between anorexia nervosa and bulimia nervosa. Clinical observations are broadly supported by the data, with restricting anorexia nervosa associated with higher levels of constraint and Persistence, and binge-purge behaviors linked to the tendency to take impulsive action when emotionally distressed. Considerable heterogeneity is found within diagnostic categories, however, suggesting that different personality structures may predispose individuals to develop disordered eating through alternative pathways.

[Genetics factors in pathogenesis and clinical genetics of binge eating disorder]

Genetic studies have shown that binge eating disorder (ВЕD) aggregates in families, heritability was estimated as about 60% and additive genetic influences on BED up to 50%. Using a genetic approach has proved useful for verifying the diagnostic categories of BED using DSM-IV criteria and supporting the validity of considering this pathology as a separate nosological category. The results confirmed the genetic and pathogenic originality of BED as a separate psychopathological phenomenon, but not a subtype of obesity. It seems fruitful to considerate BED as a disease with hereditary predisposition with significant genetic influence and a complex psychopathological syndrome, including not only eating disorders, but also depressive and addictive component. A possible mechanism of pathogenesis of BED may be the interaction of the neuroendocrine and neurotransmitters systems including the active involvement of the reward system in response to a variety of chronic stress influences with the important modulatory role of specific personality traits. The high level of genetic influence on the certain clinical manifestations of BED confirms the ability to identify the subphenotypes of BED on genetic basis involving clinical criteria. It can not only contribute to further genetic studies, taking into account more homogeneous samples, but also help in finding differentiated therapeutic approaches.

Impulsivity and test meal intake among women with bulimia nervosa

Many patients with bulimia nervosa (BN) also meet criteria for a lifetime alcohol use disorder (AUD). In order to understand possible mechanisms contributing to the co-occurrence and perpetuation of these disorders, this study investigated the importance of impulsivity and test meal intake among patients with BN by comparing women with BN only (n = 18), BN and current/past AUDs (n = 13), and healthy controls (n = 12). All participants completed assessments of eating disorder symptoms, frequency of alcohol use, binge eating, and purging via questionnaires and semi-structured interviews over two sessions. Measures of impulsivity consisted of computerized and self-report measures, and laboratory test meals. Significant differences between individuals with BN with/without comorbid AUDs were not found for test meal intake, impulsivity measures, or self-reported psychological symptoms. As hypothesized, compared to healthy controls, individuals with BN had significantly higher scores on two subscales and the total score of the Barratt Impulsiveness Scale, a trait measure of impulsivity, and consumed significantly more calories in the binge instruction meal. Total Barratt Impulsiveness Scale scores were also significantly related to kcal consumed during the laboratory test meal when individuals were instructed to binge eat (BN groups). Data from this study add to the existing literature implicating impulsivity in the psychopathology of disorders of binge eating, including BN, and also support the use of laboratory meals as a symptom-specific measure of this trait in eating disorder populations.

[Genetic aspects of binge eating disorder Part 2. Molecular genetics and pharmacogenetic approaches]

Genetic risk of binge eating disorder (ВЕD) is a consequence of joint participation of many genes, the contribution of each one is small, but the total (additive) effect is significant and greatly influences the age at onset, clinical dynamics and the level of treatment resistance. It is assumed that the carriers of different polymorphic variants of genes and their combinations have different levels of genetic risk. No Genom Wide Association studies of ВЕD has been performed and the analysis of the results of candidate genes studies gives reason to believe that pathogenetically substantiated panel of genes, including serotonin system, BDNF and, especially dopamine and endogenous opioid system, would be most useful, taking into account the mechanism of action of drugs for the ВЕD treatment. Genetic studies with this panel if using evidence-based design, detailed and quantitative analysis of the family history of binge eating can give good results for: 1) assessment of the genetic risk of ВЕD for primary prevention programs; 2) identification of the specific clinical forms of development and course of ВЕD with significant genetic influence; 3) identification of the specific genetic variants that increase the effectiveness of personalized pharmacotherapy of ВЕD within pharmacogenetic approach.

Impaired decision-making in symptomatic anorexia and bulimia nervosa patients: a meta-analysis

BACKGROUND

Impaired decision-making is a potential neurocognitive phenotype of eating disorders. It is therefore important to disentangle the decision-making deficits associated with the eating disorder subtypes and determine whether this putative impairment is a state or trait marker of the disease or more related to starvation. We systematically reviewed the literature on decision-making in eating disorders and conducted a meta-analysis to explore its role in anorexia nervosa (AN), bulimia nervosa (BN) and binge-eating disorder (BED).

METHOD

A search of the Medline and EMBASE databases and article references was performed. A total of 23 studies (2044 participants) met the selection criteria. When the Iowa gambling task (IGT) was used in at least three of the studies, a meta-analysis was run.

RESULTS

IGT performance was significantly worse in patients with an eating disorder diagnosis (AN, BN or BED) compared with healthy controls, indicating that eating disorders have a negative effect on decision-making. Hedges' g effect sizes were moderate to large (-0.72 in AN, -0.62 in BN, and -1.26 in BED). Recovered AN patients had IGT scores similar to those of healthy controls. Restrictive AN patients had significantly lower IGT net scores than purging AN patients, and both AN subtypes had worse performances than healthy controls. Age and body mass index did not explain results.

CONCLUSIONS

Decision-making was significantly altered in patients with eating disorders. Poor decision-making was more pronounced during the acute phase than in the recovered state of AN. Nutritional status during the acute phase of the disease did not seem to influence decision-making skills.

A risk and maintenance model for bulimia nervosa: From impulsive action to compulsive behavior

This article offers a new model for bulimia nervosa (BN) that explains both the initial impulsive nature of binge eating and purging, as well as the compulsive quality of the fully developed disorder. The model is based on a review of advances in research on BN and advances in relevant basic psychological science. It integrates transdiagnostic personality risk, eating-disorder-specific risk, reinforcement theory, cognitive neuroscience, and theory drawn from the drug addiction literature. We identify both a state-based and a trait-based risk pathway, and we then propose possible state-by-trait interaction risk processes. The state-based pathway emphasizes depletion of self-control. The trait-based pathway emphasizes transactions between the trait of negative urgency (the tendency to act rashly when distressed) and high-risk psychosocial learning. We then describe a process by which initially impulsive BN behaviors become compulsive over time, and we consider the clinical implications of our model. (PsycINFO Database Record

New data on psychological traits and sleep profiles of patients affected by nocturnal eating

OBJECTIVE

Nocturnal eating behavior is shared by patients affected by a parasomnia, sleep-related eating disorder (SRED), and several eating disorders such as night eating syndrome (NES) and binge-eating disorder (BED); however, the differential clinical features of these patients have been poorly studied, with persisting difficulties in defining the borders between these pathologies. The aim of this study was to evaluate polysomnographic and personality characteristics of nocturnal eaters to further differentiate the syndromes.

METHODS

During a period of six months, consecutive patients complaining of nocturnal eating were asked to participate to the study. Twenty-four patients who were found to eat during the polysomnographic recording (PSG) study, and gender-matched control subjects were included. All subjects underwent a full-night video-PSG study and a psychometric assessment including the Eating Disorder Inventory (EDI-2), the self-rating Bulimic Investigatory Test-Edinburgh (BITE), the Temperament and Character Inventory (TCI), and the Barratt Impulsivity Scale (BIS).

RESULTS

Nocturnal eaters showed a mild reduction in sleep efficiency and duration due to a moderate sleep fragmentation, whereas the percentage of each sleep stage was not significantly affected. Nocturnal eaters scored higher at many subscales of the EDI-2, at the BITE symptoms subscale, and at the BIS attentional impulsivity subscale.

CONCLUSION

The psychological characteristics found in our patients with NES seem to be typical for patients affected by eating disorders, and support the hypothesis that the nocturnal behavior of these individuals is due to an eating disorder; however, specific traits also allow differentiation of NES from BED.

An Update on Evidence-Based Psychosocial Treatments for Eating Disorders in Children and Adolescents

Eating disorders are relatively common and serious disorders in adolescents. However, there are few controlled psychosocial intervention studies with this younger population. This review updates a previous Journal of Clinical Child and Adolescent Psychology review published in 2008. The recommendations in this review were developed after searching the literature including PubMed/Medline and employing the relevant medical subject headings. In addition, the bibliographies of book chapters and treatment guideline articles were reviewed; last, colleagues were asked for suggested additional source materials. Psychosocial treatments examined include family therapy, individual therapy, cognitive behavioral therapy, interpersonal psychotherapy, cognitive training, and dialectical behavior therapy. Using the most recent Journal of Clinical Child and Adolescent Psychology methodological review criteria, family treatment-behavior (FT-B) is the only well-established treatment for adolescents with anorexia nervosa. Family treatment-systemic and insight oriented individual psychotherapy are probably efficacious treatments for adolescents with anorexia nervosa. There are no well-established treatments for adolescents with bulimia nervosa, binge eating disorder, or avoidant restrictive food intake disorder. Possibly efficacious psychosocial treatments for adolescent bulimia nervosa include FT-B and supportive individual therapy. Internet-delivered cognitive behavioral therapy is a possibly efficacious treatment for binge eating disorder. Experimental treatments for adolescent eating disorders include enhanced cognitive behavioral therapy, dialectical behavioral therapy, cognitive training, and interpersonal psychotherapy. FT-B is the only well-established treatment for adolescent eating disorders. Additional research examining treatment for eating disorders in youth is warranted.

Methylation of BDNF in women with bulimic eating syndromes: associations with childhood abuse and borderline personality disorder

DNA methylation allows for the environmental regulation of gene expression and is believed to link environmental stressors to such mental-illness phenotypes as eating disorders. Numerous studies have shown an association between bulimia nervosa (BN) and variations in brain-derived neurotrophic factor (BDNF). BDNF has also been linked to borderline personality disorder (BPD) and to such traits as reward dependence. We examined the extent to which BDNF methylation corresponded to bulimic or normal-eater status, and also to the presence of comorbid borderline personality disorder (BPD) and childhood abuse. Our sample consisted of 64 women with BN and 32 normal-eater (NE) control women. Participants were assessed for eating-disorder symptoms, comorbid psychopathology, and childhood trauma, and then they were required to provide blood samples for methylation analyses. We observed a significant site×group (BN vs. NE) interaction indicating that women with BN showed increases in methylation at specific regions of the BDNF promoter. Furthermore, examining effects of childhood abuse and BPD, we observed significant site×group interactions such that groups composed of individuals with childhood abuse or BPD had particularly high levels of methylation at selected CpG sites. Our findings suggest that BN, especially when co-occurring with childhood abuse or BPD, is associated with a propensity towards elevated methylation at specific BDNF promoter region sites. These findings imply that hypermethylation of the BDNF gene may be related to eating disorder status, developmental stress exposure, and comorbid psychopathology.

The role of temperament and character in the outcome of depressive mood in eating disorders

OBJECTIVES

The aims were to see which temperament and character dimensions were associated with depression, mainly with its outcome at two-year follow up in eating disorders (EDs).

METHODS

Participants (N=151) were 44 Anorexia nervosa (AN), 55 Bulimia nervosa (BN) and 52 Eating disorders not otherwise specified (EDNOS) patients. The Beck Depression Inventory (BDI), State and Trait Anxiety Inventory (STAI), Rosenberg Self Esteem Questionnaire (RSE), Eating Disorder Inventory (EDI-2) and Temperament and Character Inventory (TCI) were administered.

RESULTS

Depression at the beginning (t0) was severe in 22% of the cases. Harm Avoidance and Novelty Seeking had an effect on depressed mood at t0, mediated by Ineffectiveness. Responsibility (SD1) was associated with scores on the BDI at two-year follow up (β=-0.37, 95% CI -2.6, -0.6, p<0.01).

CONCLUSION

The evaluation of personality dimension in EDs has therapeutic and prognostic implications: To enhance self-efficacy and self-directness is crucial for good clinical outcome.

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.

How specific are the relationships between eating disorder behaviors and perfectionism?

Perfectionism is associated with several mental disorders, including depression, anxiety, and eating disorders. The goal of this study was to test the specificity of the associations between perfectionism facets and eating disorder behaviors, by examining whether neuroticism and conscientiousness mediated or moderated associations between these variables. Participants from a representative community sample (N = 407; 47% female) completed questionnaires assessing perfectionism, neuroticism, conscientiousness, and eating disorder behaviors. Neuroticism partially mediated associations between binge eating, restraint, body dissatisfaction, and maladaptive perfectionism facets. Neuroticism did not mediate associations between restriction and achievement striving perfectionism facets. Conscientiousness did not mediate any associations between perfectionism facets and eating disorder behaviors, yet Doubts about Actions interacted with conscientiousness to predict body dissatisfaction. Results indicate that neuroticism is key for understanding general risk factors that lead to myriad internalizing disorders, whereas maladaptive perfectionism has limited usefulness as a specific risk factor for eating disorder behaviors. Nevertheless, there is a unique association between dietary restraint and achievement striving dimensions of perfectionism that cannot be explained by higher-order personality traits.

Is attention to detail a similarly strong candidate endophenotype for anorexia nervosa and bulimia nervosa?

OBJECTIVES

To investigate whether attention to detail is a similarly strong candidate endophenotype of anorexia (AN) and bulimia nervosa (BN), and to explore the incidence and clinical correlates of attention to detail.

METHODS

A total of 266 women (including AN, BN, recovered AN, unaffected sisters of AN/BN & control women) undertook a thorough clinical assessment and were administered two neuropsychological measures of attention to detail (Group Embedded Figure Test; Rey-Osterrieth Complex Figure).

RESULTS

Superior attention to detail was found across all AN groups including recovered AN and unaffected AN sisters. Those with BN and their unaffected sisters showed a profile more consistent with poor global integration. The combined effect of superior attention to detail and poor global integration ("weak coherence") was present in 42.3% of active cases and corresponded with a more severe illness, elevated obsessive-compulsive symptoms, and a higher likelihood of comorbid clinical anxiety and self-harm.

CONCLUSIONS

Attention to detail is a stronger candidate endophenotype of AN compared to BN, where poor global integration may be more relevant. The unique contribution of both aspects of weak coherence (superior attention to detail/poor global integration) requires further exploration and understanding in both eating disorders. Integrating cognitive remediation of these traits into treatment for the subset of patients it is relevant for may improve outcome.

Incorporating dimensions into the classification of eating disorders: three models and their implications for research and clinical practice

OBJECTIVE

Given renewed interest in dimensional approaches in psychiatric nosology, we review evidence for the utility of including dimensions of eating disorder (ED) psychopathology, comorbid psychopathology, and neurobiology in the classification of EDs.

METHOD

We searched on-line databases and reference lists of published papers for articles on dimensional methods in psychiatric classification, with an emphasis on EDs.

RESULTS

ED classification may be enhanced by including dimensional assessments. Specifically, some ED features appear to exist on a continuum with normality, and dimensional measures of ED severity are likely to have utility in clinical contexts. Furthermore, accumulating data support the validity of ED classification schemes that incorporate dimensions of comorbid psychopathology. Finally, neurobiological dimensions have gained increasing notice across the psychiatric literature and may be particularly salient to the classification of EDs.

DISCUSSION

An approach to ED classification that incorporates multiple dimensional measures may have the greatest utility for advancing ED treatment.

Methylation of the glucocorticoid receptor gene promoter in bulimic women: associations with borderline personality disorder, suicidality, and exposure to childhood abuse

OBJECTIVE

To compare levels of methylation of the glucocorticoid receptor (GR) gene (NR3C1) promoter between women with bulimia nervosa (BN) and women with no eating disorder (ED), and also to explore, in women with BN, the extent to which methylation of the GR gene promoter corresponds to childhood abuse, suicidality, or borderline personality disorder (BPD).

METHOD

We measured methylation levels in selected NR3C1 promoter regions using DNA obtained from lymphocytes in 64 women with BN (32 selected as having a history of severe childhood abuse and 32 selected as having no such history) and 32 comparison women with no ED or history of childhood abuse.

RESULTS

Compared to noneating disordered women, women with BN and comorbid BPD (or BN with a history of suicidality) showed significantly more methylation of specific exon 1C sites. There was also a (nonsignificant) result indicative of greater methylation in some 1C sites among women with BN, when compared (as a group) to women with no ED. No parallel effects owing to childhood abuse were observed.

DISCUSSION

Our findings associate BN (when accompanied by BPD or suicidality) with hypermethylation of certain GR exon 1C promoter sites. We discuss theoretical and clinical implications of our findings.

Neuropsychology of eating disorders: 1995-2012

Eating disorders are considered psychiatric pathologies that are characterized by pathological worry related to body shape and weight. The lack of progress in treatment development, at least in part, reflects the fact that little is known about the pathophysiologic mechanisms that account for the development and persistence of eating disorders. The possibility that patients with eating disorders have a dysfunction of the central nervous system has been previously explored; several studies assessing the relationship between cognitive processing and certain eating behaviors have been conducted. These studies aim to achieve a better understanding of the pathophysiology of such diseases. The aim of this study was to review the current state of neuropsychological studies focused on eating disorders. This was done by means of a search process covering three relevant electronic databases, as well as an additional search on references included in the analyzed papers; we also mention other published reviews obtained by handsearching.

Epistatic interactions implicating dopaminergic genes in bulimia nervosa (BN): relationships to eating- and personality-related psychopathology

We explored the influence of interactions between polymorphisms acting upon postsynaptic receptors (DRD2 TaqA1 rs1800497 and DRD4 7R) and dopamine regulators (COMT rs4680 and DAT1) on the expression of eating symptoms and personality traits in women with bulimia-spectrum eating disorders. We had 269 bulimic women provide blood for genetic assays, and measured eating-disorder symptoms and psychopathological traits using structured interviews and self-report questionnaires. We observed two epistatic interactions on symptom indices: interactions (in predicted directions) of DRD2 by DAT were seen on Body Mass Index (p=.023), and of DRD4 by COMT on self-harming behaviors (p=.014)--with genetic effects that would correspond to reduced dopamine transmission coinciding with more-pathological scores. Our findings suggest that genes acting in the dopamine system interact to influence both eating-related and personality psychopathology, with the result that lower levels of dopamine neuro-transmission correspond to increased psychopathology and body mass in women with bulimia-spectrum disorders. We discuss the implications of our observations.

Set-shifting among adolescents with bulimic spectrum eating disorders

OBJECTIVE

Set-shifting difficulties are observed among adults with bulimia nervosa (BN). This study aimed to assess whether adolescents with BN and BN spectrum eating disorders exhibit set-shifting problems relative to healthy controls.

METHODS

Neurocognitive data from 23 adolescents with BN were compared with those from 31 adolescents with BN-type eating disorder not otherwise specified and 22 healthy controls on various measures of set-shifting (Trail Making Task [shift task], Color-Word Interference, Wisconsin Card Sorting Test, and Brixton Spatial Anticipation Task).

RESULTS

No significant differences in set-shifting tasks were found among groups (p >.35), and effect sizes were small (Cohen f < 0.17).

CONCLUSIONS

Cognitive inflexibility may develop over time because of the eating disorder, although it is possible that there is a subset of individuals in whom early neurocognitive difficulty may result in a longer illness trajectory. Future research should investigate the existence of neurocognitive taxons in larger samples and use longitudinal designs to fully explore biomarkers and illness effects.

TRIAL REGISTRATION

clinicaltrials.gov NCT00879151.

Dopamine-system genes, childhood abuse, and clinical manifestations in women with Bulimia-Spectrum Disorders

OBJECTIVE

We explored interaction effects involving polymorphisms of targeted dopamine system genes and selected forms of childhood abuse (sexual, physical and emotional) acting upon severity of binge-eating and psychopathological symptoms in women with Bulimia-Spectrum Disorders (BSDs).

METHODS

Women diagnosed with a BSD (n = 216) were assessed for childhood traumata, eating-disorder (ED) symptoms, and selected psychopathological features (sensation seeking, impulsivity, compulsivity and affective instability), and then provided blood samples for genotyping of main polymorphisms of dopamine-2 receptor (DRD2), dopamine transporter (DAT1) and catechol o-methyltransferase (COMT) genes.

RESULTS

Sensation Seeking was elevated in carriers of the low-function allele of the DRD2 Taq1A polymorphism who also reported childhood sexual abuse, relative to that in individuals showing other combinations of alleles and abuse exposures. In addition, carriers of a low-function allele of COMT scored higher on compulsivity, lower on impulsivity, and marginally lower on frequency of binge-eating than did individuals in whom the allele was absent.

DISCUSSION

Our results suggest that genes acting within the dopamine system may contribute, either directly or indirectly (i.e., in interaction with traumatic childhood experiences), to variations in the presentation of comorbid traits and, possibly, of bulimic symptoms.

Classical Stroop effect in bulimia nervosa

Bulimia nervosa (BN) is a distressing condition. Its pathogenesis is not fully understood. Neurocognitive functioning, and particularly inhibitory control, is a potential biomarker that may improve our understanding of BN. A few small-scale studies have used the classical Stroop Colour Word Test (SCWT) in BN with contradictory findings. We examined SCWT performance in a large sample of people with BN (N=72), eating disorder not otherwise specified--bulimic type (N=43) and healthy controls (N=50). The results found no difference between groups on Stroop interference effect. These findings question the utility of the classical SCWT as an assessment tool in examining executive functioning in BN.

Prospective association of common eating disorders and adverse outcomes

OBJECTIVE

Anorexia nervosa and bulimia nervosa (BN) are rare, but eating disorders not otherwise specified (EDNOS) are relatively common among female participants. Our objective was to evaluate whether BN and subtypes of EDNOS are predictive of developing adverse outcomes.

METHODS

This study comprised a prospective analysis of 8594 female participants from the ongoing Growing Up Today Study. Questionnaires were sent annually from 1996 through 2001, then biennially through 2007 and 2008. Participants who were 9 to 15 years of age in 1996 and completed at least 2 consecutive questionnaires between 1996 and 2008 were included in the analyses. Participants were classified as having BN (≥ weekly binge eating and purging), binge eating disorder (BED; ≥ weekly binge eating, infrequent purging), purging disorder (PD; ≥ weekly purging, infrequent binge eating), other EDNOS (binge eating and/or purging monthly), or nondisordered.

RESULTS

BN affected ∼1% of adolescent girls; 2% to 3% had PD and another 2% to 3% had BED. Girls with BED were almost twice as likely as their nondisordered peers to become overweight or obese (odds ratio [OR]: 1.9 [95% confidence interval: 1.0-3.5]) or develop high depressive symptoms (OR: 2.3 [95% confidence interval: 1.0-5.0]). Female participants with PD had a significantly increased risk of starting to use drugs (OR: 1.7) and starting to binge drink frequently (OR: 1.8).

CONCLUSIONS

PD and BED are common and predict a range of adverse outcomes. Primary care clinicians should be made aware of these disorders, which may be underrepresented in eating disorder clinic samples. Efforts to prevent eating disorders should focus on cases of subthreshold severity.

Interaction of the BcII glucocorticoid receptor polymorphism and childhood abuse in Bulimia Nervosa (BN): relationship to BN and to associated trait manifestations

We recently documented a gene-environment interaction suggesting that individuals with Bulimia Nervosa (BN) differed from normal eaters as to the combined presence of the low-function allele of the glucocorticoid receptor polymorphism, BcII, and childhood abuse. The present study examined the extent to which any such interaction effect may have been attributable to behavioral impulsivity, sensation seeking, affective instability or depression. We had 174 bulimic and 130 nonbulimic women provide blood for genetic assays, and measured psychopathological traits and childhood abuse using structured interviews and self-report questionnaires. As expected, we observed a significant BcII × abuse interaction indicating genetic and environmental susceptibilities to co-occur significantly more often in bulimic than in nonbulimic individuals. The BcII × abuse interaction was attenuated when levels of depression were accounted for, but was surprisingly unaffected by controls for motoric impulsivity, sensation seeking or affective instability. Our findings suggest that stress-induced alterations in glucocorticoid sensitivity contribute to BN and depressive disturbances--without being associated with the behavioral/affective dysregulation seen in many BN sufferers. We discuss theoretical and clinical implications of these observations.

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.

A study of neurocognition in bulimia nervosa and eating disorder not otherwise specified-bulimia type

Neurocognition in bulimia nervosa (BN) is under-researched. This study investigated aspects of attention (d2-Letter Cancellation Task), inhibitory control (Stroop and go/no-go task), and decision making (Game of Dice Task) in 40 people with BN, 30 with eating disorder not otherwise specified-BN type (EDNOS-BN), and 65 healthy controls (HCs). The National Adult Reading Test (NART) and Depression Anxiety Stress Scale (DASS-21) were also administered. Analyses of covariance (covariates: age, NART, and DASS-21) showed that people with BN and EDNOS-BN performed as well as HCs on all tasks. Attention task performance was poorer in the EDNOS-BN than in the BN group.

Illness perception in bulimia nervosa

The study was designed to extend our understanding of illness perceptions in patients with bulimia nervosa (BN). Seventy-eight participants with BN or BN-type Eating Disorder Not Otherwise Specified (EDNOS-BN) completed the Revised Illness Perception Questionnaire (IPQ-R) ( Moss-Morris et al., 2002 ). Clinical variables were also assessed. Participants experienced their ED as chronic, with serious consequences and high associated levels of anxiety and depression. The disorder was attributed primarily to psychological causes. The results indicate the perceived severity of BN, and high level of associated distress. These findings highlight the potential for targeting illness perceptions in treatment.

Neural correlates of the processing of self-referent emotional information in bulimia nervosa

There is increasing interest in understanding the roles of distorted beliefs about the self, ostensibly unrelated to eating, weight and shape, in eating disorders (EDs), but little is known about their neural correlates. We therefore used functional magnetic resonance imaging to investigate the neural correlates of self-referent emotional processing in EDs. During the scan, unmedicated patients with bulimia nervosa (n=11) and healthy controls (n=16) responded to personality words previously found to be related to negative self beliefs in EDs and depression. Rating of the negative personality descriptors resulted in reduced activation in patients compared to controls in parietal, occipital and limbic areas including the amygdala. There was no evidence that reduced activity in patients was secondary to increased cognitive control. Different patterns of neural activation between patients and controls may be the result of either habituation to personally relevant negative self beliefs or of emotional blunting in patients.

Neurocognition in bulimic eating disorders: a systematic review

Van den Eynde F, Guillaume S, Broadbent H, Stahl D, Campbell IC, Schmidt U, Tchanturia K. Neurocognition in bulimic eating disorders: a systematic review.

OBJECTIVE

  The aim of this study was to review the literature on neurocognition comparing people with a bulimic eating disorder in the acute phase of the illness with healthy controls (HC).

METHOD

  The review follows the PRISMA (preferred reporting items for systematic reviews and meta-analysis) statement guidelines. Three databases (Medline, Web of Science, and Scopus) were searched combining the search terms 'bulimic disorder', 'bulimia nervosa (BN)', 'binge-eating disorder (BED)' with terms referring to cognitive domains (e.g. 'executive functions').

RESULTS

  Thirty-seven studies on people with BN and four on people with BED were selected for review. Overall, sample sizes were relatively small [bulimic disorders: median and range 22 (12-83); HC: 27 (13-172)]. The diversity in methodology precluded a meta-analytical approach. People with a bulimic disorder did not present with a clear neurocognitive profile. Inclusion of salient, disorder-related stimuli (e.g. body weight/shape words) in the neurocognitive paradigms tended to generate differences between people with a bulimic disorder and HC.

CONCLUSION

  Neurocognition in bulimic eating disorders is under researched, and the available evidence is inconclusive. This review outlines strategies for further research in this area.

Contributions of the glucocorticoid receptor polymorphism (Bcl1) and childhood abuse to risk of bulimia nervosa

This study evaluated the hypothesis that traumatic stress can increase risk of bulimia nervosa (BN) in individuals who are genetically disposed towards lower modulation of physiological stress reactions. We explored the extent to which childhood abuse (physical or sexual), variants of a main glucocorticoid receptor (GR) polymorphism (Bcl1), or their interaction, differentiated women with and without BN. Women seeking treatment for BN (N=129) and non-eating-disordered comparison women (N=98) provided blood samples for assays of the Bcl1 polymorphism, and completed structured interviews assessing eating symptoms, psychiatric symptoms and childhood abuse. Compared to normal-eaters, bulimic women were significantly more likely to carry the low-function Bcl1 C allele (CC or CG genotypes), to report a history of childhood abuse and, more importantly, to be positive for both factors. We interpret our findings as indicating that traumatic stress, when impacting individuals disposed to lower GR modulation, can be etiological for BN.

The 5-HTTLPR polymorphism and eating disorders: a meta-analysis

OBJECTIVE

Eating disorders are influenced by both environmental factors and genes. The 5-HTTLPR polymorphism of serotonin transporter gene has been suggested as a good candidate. This meta-analysis was undertaken: (1) to investigate the association between 5-HTTLPR and eating disorders considered as a whole, including anorexia (AN), bulimia (BN), and binge eating disorder (BED); (2) to extend recently reported findings on the association between 5-HTTLPR and AN-BN.

METHOD

PubMed, ISI, and PsycINFO databases were searched for studies published until October 2009. Fifteen studies have been included. Data were analyzed with the Cochrane Collaboration Review Manager Software. Quality of studies and publication bias were assessed.

RESULTS

An association between S allele and eating disorders, in particular AN, has been found.

DISCUSSION

To be carrier of the 5-HTTLPR S allele seem to represent a risk factor for eating disorders, especially for AN. However, considering the reported high between-study heterogeneity, future studies should focus on more homogeneous endophenotype.

Role of the neurotrophin network in eating disorders' subphenotypes: body mass index and age at onset of the disease

Eating disorders (ED) are severe psychiatric diseases that most likely result from, and are sustained by socio-cultural, psychological and biological factors. We explored whether members of the neurotrophin family are disease-modifying factors of quantitative traits, potentially contributing to the outcome or prognosis of the disease. We studied lifetime minimum and maximum body mass index (minBMI and maxBMI) and age at onset of the disease in a sample of 991 ED patients from France, Germany, Italy and Spain and analysed 183 genetic variants located in 10 candidate genes encoding different neurotrophins and their receptors. We used a hierarchical model approach to include prior genetic knowledge of the specific and found that variants in CNTF, in its receptor CNTFR, and in NTRK2 were significantly associated with a lower age at onset of the ED. In addition, one variant in NTRK1 was associated with a higher minBMI. The results suggest that for these two subphenotypes, CNTF, CNTFR, NTRK1 and NTRK2 might act as disease-modifying factors and add preliminary evidence to the global hypothesis that EDs are the result of complex interactions and reciprocal controls between the immune, endocrine and central nervous systems.

Association between serotonin transporter gene polymorphism and eating disorders: a meta-analytic study

OBJECTIVE

Compelling evidence has suggested a role for serotonin system dysfunction in the pathogenesis of eating disorders (EDs), including anorexia nervosa (AN) and bulimia nervosa (BN). Studies have examined the association between EDs and a functional polymorphism of the serotonin transporter gene promoter (5-HTTLPR). These studies have yielded inconsistent results. The present study aimed to determine conclusively whether there is an association by using a meta-analytic method.

METHOD

Data of over 2,000 participants from eight independent case-controlassociation studies were pooled by using a random effects model.

RESULTS

AN was found to be significantly associated with the S allele (p < .001) and S carrier (SS + LS) genotype (p = .007). However, BN was associated neither with the S allele (p = .49) nor with the S carrier genotype (p = .33).

DISCUSSION

These results suggested that the genetic variance of the serotonin transporter gene promoter contributed to the susceptibility of AN.

Psychobiological traits in the risk profile for overeating and weight gain

Our dramatically changed food environment--since periods in our history when food sources were highly constrained--has presented new challenges for obesity research. For example, these alterations have strongly emphasized the physiological differences between the homeostatic and the hedonic regulation of food intake--the latter being largely responsible for the pronounced increase in obesity in the past few decades. There is also increasing agreement that compulsive overeating shares many parallels with addiction disorders such as drug abuse. These factors have also fostered a renewed interest in identifying individual differences in personality and motivational systems that increase the risk for overeating and weight gain in our population. Reward sensitivity has been the focus of a recent body of compelling research, with evidence favoring two seemingly opposite points of view. On the one hand, studies have found support for a link between low reward sensitivity and obesity, whereas other evidence suggests that a strong appetitive motivation leads to overeating and weight gain. Arguments are provided to reconcile these apparently disparate theories. Finally, the role of impulsivity and its links with symptoms of attention deficit/hyperactivity disorder are discussed, as well as their respective roles in the risk profile for obesity.

Conceptualizing the role of estrogens and serotonin in the development and maintenance of bulimia nervosa

Serotonergic dysregulation is thought to underlie much of the pathology in bulimia nervosa (BN). The purpose of this review is to expand the serotonergic model by incorporating specific and nonspecific contributions of estrogens to the development and maintenance of bulimic pathology in order to guide research from molecular genetics to novel therapeutics for BN. Special emphasis is given to the organizing theory of general brain arousal which allows for integration of specific and nonspecific effects of these systems on behavioral endpoints such as binge eating or purging as well as arousal states such as fear, novelty seeking, or sex. Regulation of the serotonergic system by estrogens is explored, and genetic, epigenetic, and environmental estrogen effects on bulimic pathology and risk factors are discussed. Genetic and neuroscientific research support this two-system conceptualization of BN with both contributions to the developmental and maintenance of the disorder. Implications of an estrogenic-serotonergic model of BN are discussed as well as guidelines and suggestions for future research and novel therapeutic targets.

The interaction between perinatal factors and childhood abuse in the risk of developing anorexia nervosa

BACKGROUND

Perinatal factors seem to be implicated in the pathogenesis of anorexia nervosa (AN) and may be involved in the programming of stress response systems in humans. Our aim was to explore one of the possible pathways to explain the association between perinatal complications and a psychiatric disorder. In particular, we tested the hypothesis that neonatal immaturity may confer an enhanced vulnerability to AN after exposure to a severe stressful event, such as childhood abuse.

METHOD

The sample was composed of subjects who took part in a prevalence study carried out on a representative sample of the general population and cases of AN referred to an out-patient specialist unit. All subjects (n=663) were born in the two obstetric wards of Padua Hospital between 1971 and 1979. We analysed data using both a case-control and a cohort design.

RESULTS

We found that functional signs of neonatal dysmaturity, but not a low birthweight or prematurity, had a significant additive interaction with childhood abuse in determining the risk for this illness. In normal subjects, but not in subjects with AN, neonatal dysmaturity was associated with being small, short or thin for gestational age at birth.

CONCLUSIONS

The synergistic effect of neonatal dysmaturity and childhood abuse in increasing the risk for AN provides evidence for the hypothesis that a prenatal programming of stress response systems can result in an impairment of the individual's resilience to severe stressful events.

Neural circuits, neurotransmitters, and behavior: serotonin and temperament in bulimic syndromes

In bulimia nervosa (BN), and in related binge-purge syndromes, factors affecting central serotonin (5-hydroxytryptamine, 5-HT) function appear to contribute not only to appetitive dysregulation but also to temperamental and personality manifestations. Drawing upon findings from neurobiological, molecular-genetic, and brain-imaging studies, we present an integrative model of the role of 5-HT function in bulimic syndromes. At the core of our model is a consideration of the ways in which diverse hereditary and environmental influences impact the action of the 5-HT system. We believe that our model helps account for heterogeneous traits seen in the bulimic population, for disproportionate representation of individuals displaying pathological personality traits and exposure to severe environmental stressors, and for interindividual variations as to treatment response.

Patterns of co-morbidity of eating disorders and substance use in Swedish females

BACKGROUND

Little is known about the association of eating disorder subtypes across multiple categories of substance use in population-based samples. We examined the association between eating disorders and substance use in a large population-based sample.

METHOD

Female participants (n=13 297) were from the Swedish Twin Registry [Lichtenstein et al., Twin Research and Human Genetics (2006) 9, 875-882]. Substance use was examined in four defined groups - (1) anorexia nervosa (AN); (2) bulimia nervosa (BN); (3) AN and BN (ANBN); and (4) binge eating disorder (BED) as well as a referent group without eating disorder (no ED). Secondary analyses examined differences between restricting AN (RAN) and binge and/or purge AN (ANBP).

RESULTS

In general, eating disorders were associated with greater substance use relative to the referent. The AN group had significantly increased odds for all illicit drugs. Significant differences emerged across the RAN and ANBP groups for alcohol abuse/dependence, diet pills, stimulants, and polysubstance use with greater use in the ANBP group. Across eating disorder groups, (1) the BN and ANBN groups were more likely to report alcohol abuse/dependence relative to the AN group, (2) the ANBN group was more likely to report diet pill use relative to the AN, BN and BED groups, and (3) the BN group was more likely to report diet pill use relative to the no ED, AN and BED groups.

CONCLUSIONS

Eating disorders are associated with a range of substance use behaviors. Improved understanding of how they mutually influence risk could enhance understanding of etiology and prevention.

The possible influence of impulsivity and dietary restraint on associations between serotonin genes and binge eating

Although serotonin (5-HT) genes are thought to be involved in the etiology of bulimia nervosa and binge eating, findings from molecular genetic studies are inconclusive. This may be due to limitations of past research, such as a failure to consider the influence of quantitative traits and gene-environment interactions. The current study investigated these issues by examining whether quantitative traits (i.e., impulsivity) and environmental exposure factors (i.e., dietary restraint) moderate 5-HT gene/binge eating associations in a sample of young women (N = 344). Binge eating was assessed using the Minnesota Eating Behavior Survey and the Dutch Eating Behavior Questionnaire (DEBQ). Impulsivity was assessed with the Barratt Impulsiveness Scale-Version 11. Dietary restraint was measured with a factor score derived from common restraint scales. Saliva samples were genotyped for the 5-HT2a receptor T102C polymorphism and 5-HT transporter promoter polymorphism. As expected, impulsivity and dietary restraint were associated with binge eating. Although the T allele of the 5-HT2a receptor gene and the s allele of the 5-HTT gene were associated with higher levels of impulsivity, there were no main effects of 5-HT genotypes on any binge eating measure, and interactions between genotypes, impulsivity, and dietary restraint were non-significant. In conclusion, we found no evidence to suggest that dietary restraint or impulsivity moderate associations between binge eating and these 5-HT genes. Future research should continue to explore interaction effects by examining larger samples, assessing dietary intake directly, and investigating other genes, traits, and environmental factors that may be related to binge eating and bulimia nervosa.

Association of trait-defined, eating-disorder sub-phenotypes with (biallelic and triallelic) 5HTTLPR variations

CONTEXT

Efforts to classify eating-disordered individuals based on concurrent personality traits have consistently converged on a typology encompassing "over-regulated", "dysregulated", and "low psychopathology" subgroups. In various populations, evidence has associated personality variations of an "over-regulated/dysregulated" type with differences on serotonin-system indices, and specifically, with different loadings of serotonin transporter promoter regulatory region polymorphism (5HTTLPR) genotypes and alleles. We explored the extent to which an empirical, trait-defined typology of eating-disordered individuals coincided systematically with variations in 5HTTLPR, assayed using biallelic and triallelic models.

METHOD

We tested 185 women with a DSM-IV eating disorder (108 with Bulimia Nervosa, 17 Anorexia Nervosa, and 60 an Eating Disorder Not Otherwise Specified) and 93 with no eating disorder on measures reflecting psychopathological traits and 5HTTLPR (biallelic and triallelic) genotypes and alleles.

RESULTS

The highest-function, triallelic (L(A)/L(A)) genotype occurred significantly more frequently among eating-disordered individuals than among controls. However, a more fine-grained analysis suggested that this association was attributable to the fact that, among eating-disordered participants, those displaying an "Inhibited/Compulsive" profile (derived using latent class analysis) were more likely than those of a "Dissocial/Impulsive" or a "Low Psychopathology" group to carry the triallelic 5HTTLPR gain-of-function L(A) allele and to be L(A)/L(A) homozygotes.

DISCUSSION

This study's empirically derived classes coincide with interpretable differences on genetic indices-associating an "Inhibited/Compulsive" group with 5HTTLPR gain-of-function genotypes (and alleles) that have elsewhere been linked to trait compulsivity. The findings, furthermore, suggest that 5HTTLPR, by influencing personality-trait manifestations may, in turn, influence eating-disorder risk and symptom expression.