Different Patterns of Emotional Eating and Visuospatial Deficits Whereas Shared Risk Factors Related with Social Support between Anorexia Nervosa and Bulimia Nervosa

Negative emotional eating patterns in general Chinese adults: A replication and expansion study examining group differences in eating disorder symptomatology, psychosocial impairment, and emotion regulation difficulties

Previous research identified four patterns of negative emotional eating in American and Chinese university students and proposed future directions (e.g., exploring potential differences in emotion regulation across patterns and replicating the patterns in a general, non-student population). Furthermore, prior research has not explored group differences in muscularity-oriented eating disorder symptomatology or psychosocial impairment. Therefore, the present study addressed these gaps in a sample of general Chinese adults, further testing group differences in typical and muscularity-oriented eating disorder symptomatology, psychosocial impairment, and emotion regulation difficulties across patterns of negative emotional eating. A total of 600 Chinese adults were recruited. Latent class analysis (LCA) was used. Results replicated the four patterns of negative emotional eating in previous research, including non-emotional eating (non-EE), emotional over- and under-eating (EOE-EUE), emotional over-eating (EOE), and emotional under-eating (EUE). Significant class differences were identified in eating disorder symptomatology, psychosocial impairment, and emotion regulation difficulties. Specifically, individuals with EOE and EOE-EUE patterns exhibited higher eating disorder symptomatology, higher psychosocial impairment, and more emotion regulation difficulties than those with non-EE and EUE patterns. Therefore, these two classes (i.e., EOE and EOE-EUE), especially the poorly researched EOE-EUE group, should be further examined to elucidate research and clinical applications. Furthermore, findings underscore the role of emotion regulation difficulties in further describing the differences across these negative emotional eating patterns, which can be considered in future interventions for reducing negative emotional eating.

Machine learning research based on diffusion tensor images to distinguish between anorexia nervosa and bulimia nervosa

Background

Anorexia nervosa (AN) and bulimia nervosa (BN), two subtypes of eating disorders, often present diagnostic challenges due to their overlapping symptoms. Machine learning has proven its capacity to improve group classification without requiring researchers to specify variables. The study aimed to distinguish between AN and BN using machine learning models based on diffusion tensor images (DTI).

Methods

This is a cross-sectional study, drug-naive females diagnosed with anorexia nervosa (AN) and bulimia nervosa (BN) were included. Demographic data and DTI were collected for all patients. Features for machine learning included Fractional anisotropy (FA), axial diffusivity (AD), radial diffusivity (RD), and mean diffusivity (MD). Support vector machine was constructed by LIBSVM, MATLAB2013b, and FSL5.0.9 software.

Results

A total of 58 female patients (24 AN, 34 BN) were included in this study. Statistical analysis revealed no significant differences in age, years of education, or course of illness between the two groups. AN patients had significantly lower BMI than BN patients. The AD model exhibited an area under the curve was 0.793 (accuracy: 75.86%, sensitivity: 66.67%, specificity: 88.23%), highlighting the left middle temporal gyrus (MTG_L) and the left superior temporal gyrus (STG_L) as differentiating brain regions. AN patients exhibited lower AD features in the STG_L and MTG_L than BN. Machine learning analysis indicated no significant differences in FA, MD, and RD values between AN and BN groups (p > 0.001).

Conclusion

Machine learning based on DTI could effectively distinguish between AN and BN, with MTG_L and STG_L potentially serving as neuroimaging biomarkers.

Is poor global processing a transdiagnostic feature of Body Dysmorphic Disorder and Anorexia Nervosa? A meta-analysis

Body dysmorphic disorder (BDD) and anorexia nervosa (AN) are characterised by body image disturbance. It has been suggested that poor global integration in visual processing may underlie distorted body image, but empirical studies have yielded mixed results. The current study involved two meta-analyses aimed at examining the extent to which poor global processing is evident in BDD and AN. Studies were identified through a systematic literature search up to October 2020. The BDD search yielded 16 studies and the AN search yielded 18 studies. Random-effect models demonstrated a small pooled effect size for BDD (g = -0.44, 95 % CI -0.70, -0.17, p < 0.001) and a moderate pooled effect size for AN (g = -0.63, 95 % CI -0.77, -0.49, p <  .001), with no evidence of significant publication bias for either. The results provide evidence that poor global processing is a transdiagnostic feature of both BDD and AN, although effects may be more pronounced in AN. Our findings highlight the possibility that interventions aimed at promoting global visual processing could prove beneficial in disorders characterised by distorted body image.

Patterns of negative emotional eating among Chinese young adults: A latent class analysis

There is ample evidence suggesting that negative emotional eating is closely related to disordered eating behaviors. However, most previous studies on the topic focused only on emotional over-eating, but neglected emotional under-eating. Moreover, previous studies also mainly used variable-oriented methods by reducing negative emotional eating to a single dimension, which limits our understanding of individual differences in negative emotional eating. In this study, we used a person-oriented approach, latent class analysis (LCA), to examine the negative emotional eating patterns and to characterize these patterns in a sample of 1,068 Chinese young adults (52.6% females, aged 17-24 years). Negative emotional eating was measured by the Emotional Over-Eating and Emotional Under-Eating subscales of the Adult Eating Behavior Questionnaire. Four patterns, namely, "non-emotional eating" (38.9%), "emotional over- and under-eating" (15.4%), "emotional over-eating" (14.7%), and "emotional under-eating" (31.0%), were identified. Sex and BMI were found to be statistically significant predictors for negative emotional eating patterns. The identified four patterns showed significant differences in eating disorder symptoms and psychological distress. Particularly, participants in emotional over- and under-eating exhibited the highest level of eating disorder symptoms and psychological distress. Overall, this study identified four distinct negative emotional eating patterns, among which, the emotional over- and under-eating was the most problematic. Future studies regarding negative emotional eating and its impact on mental health may benefit from focusing not only on individuals with emotional over-eating, but also on those showing a mixed pattern of negative emotional eating.

A systematic review of studies probing longitudinal associations between anxiety and anorexia nervosa

The current study aimed to establish whether anxiety predicts subsequent anorexia nervosa onset and maintenance. A systematic review of longitudinal studies assessing the association between stable anxiety exposures (e.g. trait anxiety/anxiety disorder pathology) and anorexia nervosa development or maintenance was undertaken. Eight studies met inclusion criteria. Seven probed the association between anxiety and anorexia nervosa onset, and one assessed the association between anxiety and anorexia nervosa maintenance. Individuals with anorexia nervosa were more likely to report childhood anxiety compared to healthy individuals, but whether childhood anxiety explains unique variance in anorexia nervosa development is unclear. Current evidence does not support longitudinal associations between specific anxiety disorders (independently of other anxiety disorders) and subsequent anorexia nervosa onset, however anxiety disorder diagnosis in general may predict increased anorexia nervosa risk. The single study probing the association between anxiety and anorexia nervosa maintenance did not find evidence supporting a relationship. The quality of individual studies was fair to high, however the body of evidence was of low quality. Further research that minimises bias, allowing for strong conclusions concerning longitudinal associations between anxiety and subsequent anorexia nervosa outcomes, is required to inform anorexia nervosa aetiology. This in turn may promote improved prevention and treatment.

Emotional over- and under-eating in early childhood are learned not inherited

Emotional overeating (EOE) has been associated with increased obesity risk, while emotional undereating (EUE) may be protective. Interestingly, EOE and EUE tend to correlate positively, but it is unclear whether they reflect different aspects of the same underlying trait, or are distinct behaviours with different aetiologies. Data were from 2054 five-year-old children from the Gemini twin birth cohort, including parental ratings of child EOE and EUE using the Child Eating Behaviour Questionnaire. Genetic and environmental influences on variation and covariation in EUE and EOE were established using a bivariate Twin Model. Variation in both behaviours was largely explained by aspects of the environment completely shared by twin pairs (EOE: C = 90%, 95% CI: 89%-92%; EUE: C = 91%, 95% CI: 90%-92%). Genetic influence was low (EOE: A = 7%, 95% CI: 6%-9%; EUE: A = 7%, 95% CI: 6%-9%). EOE and EUE correlated positively (r = 0.43, p < 0.001), and this association was explained by common shared environmental influences (BivC = 45%, 95% CI: 40%-50%). Many of the shared environmental influences underlying EUE and EOE were the same (r_C = 0.50, 95% CI: 0.44, 0.55). Childhood EOE and EUE are etiologically distinct. The tendency to eat more or less in response to emotion is learned rather than inherited.

Factors Predicting an Escalation of Restrictive Eating During Adolescence

PURPOSE

To examine longitudinal risk factors and short-term risk correlates for the development of extreme forms of restrictive eating among adolescent dieters.

METHODS

Data from Project Eating and Activity in Teens and Young Adults, a population-based study of 2,516 students aged 12-18 years, were collected in 1998-1999 (Time 1) and 5 years later (Time 2). Within this sample, 243 adolescents who reported dieting but not engaging in disordered forms of restrictive eating (e.g., fasting, skipping meals) at Time 1 were followed to determine the self-reported psychological, familial, and social variables predicting initiation of disordered restrictive eating at Time 2. To investigate short-term risk correlates of initiating disordered restrictive eating, the same risk factors were also compared cross-sectionally at Time 2 between the dieters who had and had not initiated disordered restrictive eating. Poisson regression models with robust standard errors were fit for each predictor adjusted for covariates.

RESULTS

Depressive symptoms and low self-esteem were significantly associated with the initiation of disordered restrictive eating in both longitudinal and cross-sectional analyses. Poor family communication/caring and maternal dieting significantly predicted long-term risk for escalating restrictive eating severity; whereas, individual body image issues (i.e., weight concerns, body dissatisfaction) and social concerns (i.e., weight-related teasing, peer dieting) were significant short-term correlates of initiating disordered restrictive eating.

CONCLUSIONS

Depressive symptoms and low self-esteem may be especially important targets for risk identification and prevention for disordered restrictive eating. Intervening on family influences may decrease long-term risk, whereas intervening on body image and responses to social influences may decrease short-term risk for disordered restrictive eating.

Does depression matter in neuropsychological performances in anorexia nervosa? A descriptive review

OBJECTIVE

This review aims to examine the impact of depressive symptoms on the assessment of cognitive flexibility, central coherence, and decision-making in individuals with anorexia nervosa (AN).

METHOD

An online search was carried out using PubMed and PsycInfo. Articles were selected for review if they were published in English between 1990 and 2014 and used the Wisconsin Card Sorting Test, the Trail Making Task parts A and B, the Brixton Test, the Rey-Osterrieth Complex Figure Test, and/or the Iowa Gambling Task.

RESULTS

Sixty-two studies were included. Thirty (48%) of the studies statistically assessed the association between depression and neurocognition in AN versus healthy controls. Where significant correlations were found, it became clear that the more serious the depression, the greater the neuropsychological impairment. Only six (10%) studies examined whether increased depressive symptoms were able to eliminate the differences between individuals with AN and healthy controls, and one study found that depressive symptoms did eliminate group differences in cognitive flexibility and decision-making.

DISCUSSION

Only a subgroup of articles on neuropsychology in AN adjusted for depression. However, given the role of depression that some articles suggest, future studies should pay closer attention to the evaluation of this potential confounder.

Central Coherence, Visuoconstruction and Visual Memory in Patients with Eating Disorders as Measured by Different Scoring Methods of the Rey Complex Figure Test

OBJECTIVE

The aims of this study were to examine the performance of eating disorder (ED) patients on the Rey Complex Figure Test and to investigate the validity of the Q-score as a new method for measuring central coherence (CC).

METHOD

Forty-one patients with anorexia nervosa, 40 patients with bulimia nervosa and 40 healthy controls completed the Rey Complex Figure Test, which was scored both quantitatively and qualitatively.

RESULTS

Both ED groups scored lower than the healthy controls on copy, recall and the Q-score. For the anorexia nervosa group, performance on the Central Coherence Index was associated with the nadir body mass index. Performance on the recall measures was independently associated with the nadir body mass index and depressive symptoms for the bulimia nervosa group. There was a strong correlation between the Q-score and the Central Coherence Index (r = 0.77).

DISCUSSION

The study reveals different levels of CC and suggests that the Q-score might be an applicable method for measuring CC in ED patients.

Anorexia nervosa and body dysmorphic disorder are associated with abnormalities in processing visual information

BACKGROUND

Anorexia nervosa (AN) and body dysmorphic disorder (BDD) are characterized by distorted body image and are frequently co-morbid with each other, although their relationship remains little studied. While there is evidence of abnormalities in visual and visuospatial processing in both disorders, no study has directly compared the two. We used two complementary modalities--event-related potentials (ERPs) and functional magnetic resonance imaging (fMRI)--to test for abnormal activity associated with early visual signaling.

METHOD

We acquired fMRI and ERP data in separate sessions from 15 unmedicated individuals in each of three groups (weight-restored AN, BDD, and healthy controls) while they viewed images of faces and houses of different spatial frequencies. We used joint independent component analyses to compare activity in visual systems.

RESULTS

AN and BDD groups demonstrated similar hypoactivity in early secondary visual processing regions and the dorsal visual stream when viewing low spatial frequency faces, linked to the N170 component, as well as in early secondary visual processing regions when viewing low spatial frequency houses, linked to the P100 component. Additionally, the BDD group exhibited hyperactivity in fusiform cortex when viewing high spatial frequency houses, linked to the N170 component. Greater activity in this component was associated with lower attractiveness ratings of faces.

CONCLUSIONS

Results provide preliminary evidence of similar abnormal spatiotemporal activation in AN and BDD for configural/holistic information for appearance- and non-appearance-related stimuli. This suggests a common phenotype of abnormal early visual system functioning, which may contribute to perceptual distortions.

Aberrant early visual neural activity and brain-behavior relationships in anorexia nervosa and body dysmorphic disorder

BACKGROUND

Body dysmorphic disorder (BDD) and anorexia nervosa (AN) share the clinical symptom of disturbed body image, which may be a function of perceptual distortions. Previous studies suggest visual or visuospatial processing abnormalities may be contributory, but have been unable to discern whether these occur early or late in the visual processing stream. We used electroencephalography (EEG) and visual event related potentials (ERP) to investigate early perceptual neural activity associated with processing visual stimuli.

METHODS

We performed EEG on 20 AN, 20 BDD, 20 healthy controls, all unmedicated. In order to probe configural/holistic and detailed processing, participants viewed photographs of faces and houses that were unaltered or filtered to low or high spatial frequencies, respectively. We calculated the early ERP components P100 and N170, and compared amplitudes and latencies among groups.

RESULTS

P100 amplitudes were smaller in AN than BDD and healthy controls, regardless of spatial frequency or stimulus type (faces or houses). Similarly, N170 latencies were longer in AN than healthy controls, regardless of spatial frequency or stimulus type, with a similar pattern in BDD at trend level significance. N170 amplitudes were smaller in AN than controls for high and normal spatial frequency images, and smaller in BDD than controls for normal spatial frequency images, regardless of stimulus type. Poor insight correlated with lower N170 amplitudes for normal and low spatial frequency faces in the BDD group.

CONCLUSIONS

Individuals with AN exhibit abnormal early visual system activity, consistent with reduced configural processing and enhanced detailed processing. This is evident regardless of whether the stimuli are appearance-or non-appearance-related, and thus may be a reflection of general, early perceptual abnormalities. As N170 amplitude could be a marker of structural encoding of faces, lower values may be associated with perceptual distortions and could contribute to poor insight in BDD. Future studies may explore visual ERP measures as potential biomarkers of illness phenotype.

Recent Advances in Developmental and Risk Factor Research on Eating Disorders

The Diagnostic and Statistical Manual of Mental Disorders (i.e., DSM-5) currently recognizes three primary eating disorders: anorexia nervosa, bulimia nervosa, and binge eating disorder. The origins of eating disorders are complex and remain poorly understood. However, emerging research highlights a dimensional approach to understanding the multifactorial etiology of eating disorders as a means to inform assessment, prevention, and treatment efforts. Guided by research published since 2011, this review summarizes recent findings elucidating risk factors for the development of eating disorders across the lifespan in three primary domains: (1) genetic/biological, (2) psychological, and (3) socio-environmental. Prospective empirical research in clinical samples with full-syndrome eating disorders is emphasized with added support from cross-sectional studies, where relevant. The developmental stages of puberty and the transition from adolescence to young adulthood are discussed as crucial periods for the identification and prevention of eating disorders. The importance of continuing to elucidate the mechanisms underlying gene by environmental interactions in eating disorder risk is also discussed. Finally, controversial topics in the field of eating disorder research and the clinical implications of this research are summarized.

Employing executive functions of perceptual and memory abilities in underweight and weight-restored anorexia nervosa patients

PURPOSE

Executive functions (EF) have been widely investigated in anorexia nervosa (AN) revealing difficulties in various aspects. We aimed at testing the effects of EF on stimuli perception and its representations in memory.

METHODS

Thirty AN underweight patients, 30 weight-restored AN patients, and 44 control participants, were recruited. Various EF were assessed using the Rey-Osterrieth Complex Figure Test, analyzed with the Boston Qualitative Scoring System.

RESULTS

No differences were found in visuo-constructional measures in either AN groups compared to controls on the copy and memory stages. However, both groups performed significantly worse than controls on most EF variables in the copy stage, while in the immediate and delayed memory stages the difference was less substantial.

CONCLUSIONS

Difficulties in EF among AN patients, current and weight restored, are more pronounced in the perceptual module and less so when employed through memory retrieval. The pattern, which is apparent after weight gain, suggests that there is no ameliorative effect on these difficulties.

Central coherence in eating disorders: an updated systematic review and meta-analysis

OBJECTIVES

A bias towards local information over the global "gist" (weak central coherence, WCC), has been identified as a possible contributing and maintaining factor in eating disorders (ED). The present study aimed to provide an updated review of the WCC literature and examine the hypothesis that individuals with ED have WCC.

METHODS

The new search found 12 eligible studies. Meta-analyses were performed on nine of these 12 studies, the remaining three were commented on individually. Data were combined with data from the previous 2008 review, and meta- analyses were performed on 16 studies (nine studies from the new search and seven studies from 2008 review).

RESULTS

Meta-analysis of the Group Embedded Figures Task provided evidence of superior local processing across all ED subtypes (pooled effect size of d = -0.62 (95% CI = -0.94, -0.31), P < 0.001). Evidence of poorer global processing in ED groups was found from meta-analyses of the Rey-Osterrieth Complex Figures task (d = -0.63 (95% CI = -0.77, -0.49, P < 0.001), and the Object Assembly Task (d = -0.65 (95% CI = -0.94, -0.37), P < 0.0001).

CONCLUSIONS

As well as supporting the results of previous studies by providing evidence of inefficient global processing, this review has provided evidence of superior local processing, which supports the WCC hypothesis in ED.

Intellectual function in patients with anorexia nervosa and bulimia nervosa

OBJECTIVE

This study aimed to examine cognitive function in individuals with anorexia nervosa (AN) and bulimia nervosa (BN) on the basis of IQ measures, indexes and subtests of the Wechsler Adult Intelligence Scale – Third Edition (WAIS-III).

METHODS

A total of 41 patients with AN, 40 patients with BN and 40 healthy controls (HC), matched for sex, age and education, were recruited consecutively to complete the WAIS-III.

RESULTS

The AN group showed a significantly lower performance than the HC group on most global measures and on eight of the 13 administered subtests. Minor differences in verbal function were detected between the BN group and the HC group.

CONCLUSION

The patients with eating disorders showed normal intellectual functions compared with the normative population. However, the AN group displayed a consistently lower performance than the matched HC group, which performed above normative means. The BN group performed at a level between that of the AN and HC groups.

Visual processing in anorexia nervosa and body dysmorphic disorder: similarities, differences, and future research directions

Anorexia nervosa (AN) and body dysmorphic disorder (BDD) are psychiatric disorders that involve distortion of the experience of one's physical appearance. In AN, individuals believe that they are overweight, perceive their body as "fat," and are preoccupied with maintaining a low body weight. In BDD, individuals are preoccupied with misperceived defects in physical appearance, most often of the face. Distorted visual perception may contribute to these cardinal symptoms, and may be a common underlying phenotype. This review surveys the current literature on visual processing in AN and BDD, addressing lower- to higher-order stages of visual information processing and perception. We focus on peer-reviewed studies of AN and BDD that address ophthalmologic abnormalities, basic neural processing of visual input, integration of visual input with other systems, neuropsychological tests of visual processing, and representations of whole percepts (such as images of faces, bodies, and other objects). The literature suggests a pattern in both groups of over-attention to detail, reduced processing of global features, and a tendency to focus on symptom-specific details in their own images (body parts in AN, facial features in BDD), with cognitive strategy at least partially mediating the abnormalities. Visuospatial abnormalities were also evident when viewing images of others and for non-appearance related stimuli. Unfortunately no study has directly compared AN and BDD, and most studies were not designed to disentangle disease-related emotional responses from lower-order visual processing. We make recommendations for future studies to improve the understanding of visual processing abnormalities in AN and BDD.

Central coherence in full recovery of anorexia nervosa

OBJECTIVE

This study examined central coherence as a possible endophenotype in a large sample of women recovered from anorexia nervosa (rec AN). Recovery was defined by considering physiological, behavioural and psychological variables.

METHOD

A total of 100 rec AN women and 100 healthy women completed the Rey Complex Figure Test, a measure for visual-spatial central coherence. The participants were matched 1:1 for age and educational level.

RESULTS

Compared with the healthy control group, the rec AN group showed better accuracy in the copy condition. There was a trend for a local strategy in the rec AN group compared with a global strategy in the healthy control group.

CONCLUSIONS

This sample of rec AN women showed no inefficiencies in global processing but a superior local processing after full recovery from AN.

Social cognition in anorexia nervosa: evidence of preserved theory of mind and impaired emotional functioning

BACKGROUND

The findings of the few studies that have to date investigated the way in which individuals with Anorexia Nervosa (AN) navigate their social environment are somewhat contradictory. We undertook this study to shed new light on the social-cognitive profile of patients with AN, analysing Theory of Mind and emotional functioning. Starting from previous evidence on the role of the amygdala in the neurobiology of AN and in the social cognition, we hypothesise preserved Theory of Mind and impaired emotional functioning in patients with AN.

METHODOLOGY

Thirty women diagnosed with AN and thirty-two women matched for education and age were involved in the study. Theory of Mind and emotional functioning were assessed with a set of validated experimental tasks. A measure of perceived social support was also used to test the correlations between this dimension and the social-cognitive profile of AN patients.

PRINCIPAL FINDINGS

The performance of patients with AN is significantly worse than that of healthy controls on tasks assessing emotional functioning, whereas patients' performance is comparable to that of healthy controls on the Theory of Mind task. Correlation analyses showed no relationship between scores on any of the social-cognition tasks and either age of onset or duration of illness. A correlation between social support and emotional functioning was found. This latter result seems to suggest a potential role of social support in the treatment and recovery of AN.

CONCLUSIONS

The pattern of results followed the experimental hypothesis. They may be useful to help us better understand the social-cognitive profile of patients with AN and to contribute to the development of effective interventions based on the ways in which patients with AN actually perceive their social environment.

Low social interactions in eating disorder patients in childhood and adulthood: A multi-centre European case control study

The objective of this article was to examine lifestyle behaviours in eating disorder (ED) patients and healthy controls. A total of 801 ED patients and 727 healthy controls from five European countries completed the questions related to lifestyle behaviours of the Cross-Cultural Questionnaire (CCQ). For children, the ED sample exhibited more solitary activities (rigorously doing homework [p<0.001] and watching TV [p<0.05] and less socializing with friends [p<0.05]) than the healthy control group and this continued in adulthood. There were minimal differences across ED sub-diagnoses and various cross-cultural differences emerged. Reduced social activities may be an important risk and maintaining factor for ED symptomatology.