Current status of functional imaging in eating disorders

Neural underpinnings of threat bias in relation to loss-of-control eating behaviors among adolescent girls with high weight

Introduction

Loss-of-control (LOC) eating, a key feature of binge-eating disorder, may relate attentional bias (AB) to highly salient interpersonal stimuli. The current pilot study used magnetoencephalography (MEG) to explore neural features of AB to socially threatening cues in adolescent girls with and without LOC-eating.

Methods

Girls (12-17 years old) with overweight or obesity (BMI >85th percentile) completed an AB measure on an affective dot-probe AB task during MEG and evoked neural responses to angry or happy (vs. neutral) face cues were captured. A laboratory test meal paradigm measured energy intake and macronutrient consumption patterns.

Results

Girls (N = 34; Mage = 15.5 ± 1.5 years; BMI-z = 1.7 ± 0.4) showed a blunted evoked response to the presentation of angry face compared with neutral face cues in the left dorsolateral prefrontal cortex, a neural region implicated in executive control and regulation processes, during attention deployment (p < 0.01). Compared with those without LOC-eating (N = 21), girls with LOC-eating (N = 13) demonstrated a stronger evoked response to angry faces in the visual cortex during attention deployment (p < 0.001). Visual and cognitive control ROIs had trends suggesting interaction with test meal intake patterns among girls with LOC-eating (ps = 0.01).

Discussion

These findings suggest that girls with overweight or obesity may fail to adaptively engage neural regions implicated in higher-order executive processes. This difficulty may relate to disinhibited eating patterns that could lead to excess weight gain.

The effects of acute tryptophan depletion on instrumental reward learning in anorexia nervosa - an fMRI study

BACKGROUND

The serotonin (5-HT) hypothesis of anorexia nervosa (AN) posits that individuals predisposed toward or recovered from AN (recAN) have a central nervous hyperserotonergic state and therefore restrict food intake as a means to reduce 5-HT availability (via diminished tryptophan-derived precursor supply) and alleviate associated negative mood states. Importantly, the 5-HT system has also been generally implicated in reward processing, which has also been shown to be altered in AN.

METHODS

In this double-blind crossover study, 22 individuals recAN and 25 healthy control participants (HC) underwent functional magnetic resonance imaging (fMRI) while performing an established instrumental reward learning paradigm during acute tryptophan depletion (ATD; a dietary intervention that lowers central nervous 5-HT availability) as well as a sham depletion.

RESULTS

On a behavioral level, the main effects of reward and ATD were evident, but no group differences were found. fMRI analyses revealed a group × ATD × reward level interaction in the ventral anterior insula during reward anticipation as well as in the medial orbitofrontal cortex during reward consumption.

DISCUSSION

The precise pattern of results is suggestive of a 'normalization' of reward-related neural responses during ATD in recAN compared to HC. Our results lend further evidence to the 5-HT hypothesis of AN. Decreasing central nervous 5-HT synthesis and availability during ATD and possibly also by dieting may be a means to normalize 5-HT availability and associated brain processes.

Food Restriction in Anorexia Nervosa in the Light of Modern Learning Theory: A Narrative Review

Improvements in the clinical management of anorexia nervosa (AN) are urgently needed. To do so, the search for innovative approaches continues at laboratory and clinical levels to translate new findings into more effective treatments. In this sense, modern learning theory provides a unifying framework that connects concepts, methodologies and data from preclinical and clinical research to inspire novel interventions in the field of psychopathology in general, and of disordered eating in particular. Indeed, learning is thought to be a crucial factor in the development/regulation of normal and pathological eating behaviour. Thus, the present review not only tries to provide a comprehensive overview of modern learning research in the field of AN, but also follows a transdiagnostic perspective to offer testable explanations for the origin and maintenance of pathological food rejection. This narrative review was informed by a systematic search of research papers in the electronic databases PsycInfo, Scopus and Web of Science following PRISMA methodology. By considering the number and type of associations (Pavlovian, goal-directed or habitual) and the affective nature of conditioning processes (appetitive versus aversive), this approach can explain many features of AN, including why some patients restrict food intake to the point of life-threatening starvation and others restrict calorie intake to lose weight and binge on a regular basis. Nonetheless, it is striking how little impact modern learning theory has had on the current AN research agenda and practice.

Obesity mechanism after hypothalamic damage: Cohort analysis of neuroimaging, psychological, cognitive, and clinical phenotyping data

OBJECTIVE

The hypothalamus regulates energy homeostasis, and its damage results in severe obesity. We aimed to investigate the multifaceted characteristics of hypothalamic obesity.

METHODS

We performed multidimensional analyses of brain structure/function and psychological and behavioral phenotypes in 29 patients with hypothalamic damage (HD) (craniopharyngioma) and 31 controls (non-functional pituitary adenoma). Patients underwent structural and functional magnetic resonance imaging and completed self-reports and cognitive tasks.

RESULTS

Patients with HD showed significantly higher postoperative weight gain than controls. The HD group also showed significant hypothalamic damage and lower neural activation in the left caudate nucleus in response to food images. The HD group had significantly higher food inattention, lower satiety, and higher restrained eating behavior. Within the HD group, higher restrained eating behavior was significantly associated with lower activation in the bilateral fusiform gyrus.

CONCLUSION

These results suggest that hypothalamic damage contributes to weight gain by altering the brain response, attention, satiety, and eating behaviors. The present study proposes novel neuro-psycho-behavioral mechanisms targeted for patients with hypothalamic obesity.

The neural correlates of socio-cognitive factors and eating disorders in young people: A systematic review

BACKGROUND

Although the primary aetiology of Eating Disorders (ED) remains unknown, research suggests a complex interplay of biological, psychological, and cultural/environmental factors. This paper aims to systematically review the literature on neuroimaging studies that measure socio-cognitive factors, in the context of body dissatisfaction and EDs in young people. Specifically, our aim was to identify patterns in the findings linked to social media-type behaviours.

METHODS

The review was conducted in accordance with PRISMA guidelines using PubMed, Scopus, and Web of Science databases. 799 papers were identified in the database search and 38 studies were selected based on exclusion and inclusion criteria. Selected studies were assessed using the National Institute of Health study quality assessment tool.

RESULTS

Findings point to state-related impairments in inhibitory control and salient emotional processing. Anorexia Nervosa(AN) showed impaired set-shifting abilities, working memory and decision making, while altered activation in attention networks and associated difficulties with conflict resolution were seen for Bulimia Nervosa(BN) and Other Specified Feeding and Eating Disorders(OSFED). AN and BN also demonstrated altered sensitivity to food-related stimuli in striatal regions, suggesting aberrant top-down emotional-cognitive control. ED participants also show deficits in body representation, impaired control over social behaviours and altered integration of visual and body perception.

DISCUSSION

These findings support the notion that socio-cognitive dysfunctions in ED are underpinned by a distributed network of structural and functional brain changes which influence the way young people with ED interact with and respond to social media, and ultimately places at them at increased risk for body image disturbances. This Review was registered with the PROSPERO International Register of Systematic Reviews, Registration number CRD42021270696.

Non-verbal social communication in individuals with eating disorders: an ethological analysis in experimental setting

PURPOSE

Evidence that social difficulties promote the development and the maintenance of eating disorders (EDs) derive from self-reported data and only partially from experimental tasks. This study objectively assessed non-verbal behaviors of individuals with EDs in a psycho-social stress scenario.

METHODS

Thirty-one women suffering from EDs (13 with anorexia nervosa and 18 with bulimia nervosa) and 15 healthy women underwent the Trier Social Stress Test (TSST), the paradigm of psycho-social stress, and were videotaped. Throughout the procedure, anxiety feelings were measured by the State-Trait Anxiety Inventory state subscale and saliva samples were collected to evaluate cortisol levels. Non-verbal behaviors were analyzed through the Ethological Coding System for Interviews and were compared between study samples through multivariate analysis of variance. Multivariate regression analyses were performed to assess the association between anxiety, cortisol and behavioral responses to TSST.

RESULTS

Women with EDs showed reduced submissiveness, flight (cutoff from social stimuli) and gesture compared to healthy peers during TSST. Submissiveness and flight behaviors were negatively associated with stress-induced anxiety, while TSST-induced anxiety and cortisol increases were positively associated with looking at the other's face behavior in participants with EDs. In this population, cortisol reactivity was also positively associated with submissiveness and negatively with gesture.

CONCLUSION

Women with EDs showed a hostile and freezing response to acute psycho-social stress: reduced submissiveness and flight may represent strategies to manage social anxiety. These findings confirm that the non-verbal behavior assessment provides complementary information to those derived from traditional measurements and suggests research and clinical implications.

LEVEL OF EVIDENCE I

Evidence obtained from experimental study.

The sight of one’s own body: Could qEEG help predict the treatment response in anorexia nervosa?

Aims of the study

The study aims to identify the differences in brain activity between participants with anorexia nervosa and healthy control using visual stimulus conditions combined with the quantitative dense-array EEG recording analysis method called Brain Activation Sequences (BAS).

Materials and methods

23 participants with anorexia nervosa and 21 healthy controls were presented with visual stimuli, including the subject’s facial expressions and body images. The 128-channel EEG data were processed using BAS and displayed as activity in up to 66 brain regions. Subsequent cluster analysis was used to identify groups of participants exhibiting area-specific activation patterns.

Results

Cluster analysis identified three distinct groups: one including all healthy controls (HC) and two consisting of all participants with anorexia (AN-I with 19 participants and AN-II with four participants). The AN-I and AN-II groups differed in their response to treatment. Comparisons of HC vs. AN confirmed the dominance of the right cerebral hemisphere in participants with anorexia nervosa in two of the three reported conditions. The facial expressions condition, specifically the facial reaction expressing disgust, indicates the existence of a social attentional bias toward faces, whereas emotions remained undetected in participants. High limbic activity, medial frontal gyrus involvement, low fusiform cortex activity, and milder visual cortex activity in healthy controls compared to participants indicate that the facial expression stimulus is perceived by healthy subjects primarily as an emotion, not as the face itself. In the body image condition, participants showed higher activity in the fusiform gyrus and right insula, indicating activation of the brain’s “fear network.”

Conclusion

The study describes a specific pattern of brain activation in response to facial expression of disgust and body images that likely contributes to social-cognitive and behavioral impairments in anorexia. In addition, the substantial difference in the pattern of brain activation within the participants with AN and its association with treatment resistance deserves special attention because of its potential to develop a clinically useful prediction tool and identify potential targets for, for example, neuromodulatory treatments and/or individualized psychotherapy.

Affect Modulated Startle Response in Anorexia Nervosa, Restricting Type: Implications for Theory and Practice

Objective: Individuals with anorexia nervosa (AN), restricting type demonstrate unique emotional responses to hedonically positive stimuli beyond eating disorder (ED)-related stimuli. The goal of this study was to evaluate differences in responses to five types of emotionally positive stimuli among acutely ill anorexia nervosa (IAN), restricting type patients, weight-recovered anorexia patients (WRAN), and healthy controls (HCs) using affect modulated startle response (AMSR) as an objective measure.

Method: A total of 28 participants were recruited (n=28). Fourteen participants were recruited as IAN using the Diagnostic and Statistical Manual of Mental Disorders-V (DSM-V) criteria, seven were WRAN, and seven were HC females. All participants were female and aged between 8 and 18 years. The participants viewed images depicting negative, neutral, standardized, and non-eating disorder (ED)-related positive stimuli. Additionally, four categories of ED-related stimuli (high-calorie food, body image, success, and parent-child relationships) were presented to all participants during a standard AMSR paradigm.

Results: No significant between-group differences were found for any of the four ED stimulus categories; all groups showed an inhibited startle response to the four ED-related categories. In contrast, IAN and WRAN showed reduced hedonic responses to standardized positive stimuli relative to HC-replicating previous results. Reduced hedonic response to the standardized (non-ED) positive stimuli was highly correlated with self-reported social anxiety, low self-esteem, body dissatisfaction, asceticism, interpersonal problems, and ineffectiveness.

Conclusion: AN patients had a reduced hedonic response to some non-ED-related positive stimuli, which correlated with several anxiety-related traits. In contrast, their early automatic responses to high-calorie food, normal weight models, images of success, and positive parent-child relationships did not differ from HC, suggesting these stimuli are either being evaluated as highly interesting or hedonically positive.

The Utility of Animal Models for Studying the Metabo-Psychiatric Origins of Anorexia Nervosa

Anorexia nervosa (AN) is a severe eating disorder that primarily affects young women and girls, and is characterized by abnormal restrictive feeding and a dangerously low body-mass index. AN has one of the highest mortality rates of any psychiatric disorder, and no approved pharmacological treatments exist. Current psychological and behavioral treatments are largely ineffective, and relapse is common. Relatively little basic research has examined biological mechanisms that underlie AN compared to other major neuropsychiatric disorders. A recent large-scale genome-wide association study (GWAS) revealed that the genetic architecture of AN has strong metabolic as well as psychiatric origins, suggesting that AN should be reconceptualized as a metabo-psychiatric disorder. Therefore, identifying the metabo-psychiatric mechanisms that contribute to AN may be essential for developing effective treatments. This review focuses on animal models for studying the metabo-psychiatric mechanisms that may contribute to AN, with a focus on the activity-based anorexia (ABA) paradigm. We also highlight recent work using modern circuit-dissecting neuroscience techniques to uncover metabolic mechanisms that regulate ABA, and encourage further work to ultimately identify novel treatment strategies for AN.

Deep brain stimulation (DBS) in resistant mental disorders

Introduction: Deep Brain Stimulation can directly alter brain activity in a controlled manner and the effect is reversible. The mechanism is that the electrode acts locally on neural activity, which is transferred to monosynchronous and multisynaptic network connections.

Methods: We present studies conducted on a group of patients that show an improvement in mental state after Deep Brain Stimulation.

Material: The diseases we included in our work are: Obsessive-Compulsive Disorder, Eating Disorder, Depression and Bipolar Affective Disorder.

Discussion: The use of deep brain stimulation can inhibit development of acute state of patients and improve both psychiatric features and the time of remission. The results indicate the greatest effectiveness of Deep Brain Stimulation in Obsessive-Compulsive Disorders.

Conclusions: Brain stimulation may be a promising therapeutic target in mental illness. In a properly selected location, it can contribute to a significant clinical improvement however further research in this direction is necessary.

Backstage of Eating Disorder-About the Biological Mechanisms behind the Symptoms of Anorexia Nervosa

Anorexia nervosa (AN) represents a disorder with the highest mortality rate among all psychiatric diseases, yet our understanding of its pathophysiological components continues to be fragmentary. This article reviews the current concepts regarding AN pathomechanisms that focus on the main biological aspects involving central and peripheral neurohormonal pathways, endocrine function, as well as the microbiome-gut-brain axis. It emerged from the unique complexity of constantly accumulating new discoveries, which hamper the ability to look at the disease in a more comprehensive way. The emphasis is placed on the mechanisms underlying the main symptoms and potential new directions that require further investigation in clinical settings.

Intolerance of uncertainty moderates the relationship between high personal standards but not evaluative concerns perfectionism and eating disorder symptoms cross-sectionally and prospectively

Two dimensions of perfectionism related to eating disorder (ED) symptoms are evaluative concerns and high standards. Evaluative concerns are consistently linked with ED symptoms, whereas there are conflicting results regarding high standards and ED symptoms. High standards are unrelated to ED symptoms in some studies and are linked to higher ED symptoms in others. Intolerance of uncertainty (IU) may influence the relation between high standards and ED symptoms; individuals elevated in both IU and high standards may find it distressing to be uncertain about future situations for fear of not living up to high expectations and use ED behaviors to cope with such uncertainty. In the current study (N = 216), we explored whether IU moderates the relationships between high standards and evaluative concerns and ED symptoms, both cross-sectionally and prospectively across two weeks. IU significantly moderated high standards and ED symptoms both cross-sectionally and across time while accounting for baseline ED symptoms, but did not moderate the relationship between evaluative concerns and ED symptoms. Higher standards were associated with greater ED symptoms in individuals higher, but not lower in IU. These findings suggest high standards may only contribute to ED symptoms when individuals are also high in IU.

Altered thalamo–cortical and occipital–parietal– temporal–frontal white matter connections in patients with anorexia and bulimia nervosa: a systematic review of diffusion tensor imaging studies

BACKGROUND

Anorexia nervosa and bulimia nervosa are complex mental disorders, and their etiology is still not fully understood. This paper reviews the literature on diffusion tensor imaging studies in patients with anorexia nervosa and bulimia nervosa to explore the usefulness of white matter microstructural analysis in understanding the pathophysiology of eating disorders.

METHODS

We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines to identify diffusion tensor imaging studies that compared patients with an eating disorder to control groups. We searched relevant databases for studies published from database inception to August 2018, using combinations of select keywords. We categorized white matter tracts according to their 3 main classes: projection (i.e., thalamo–cortical), association (i.e., occipital–parietal–temporal–frontal) and commissural (e.g., corpus callosum).

RESULTS

We included 19 papers that investigated a total of 427 participants with current or previous eating disorders and 444 controls. Overall, the studies used different diffusion tensor imaging approaches and showed widespread white matter abnormalities in patients with eating disorders. Despite differences among the studies, patients with anorexia nervosa showed mainly white matter microstructural abnormalities of thalamo–cortical tracts (i.e., corona radiata, thalamic radiations) and occipital–parietal–temporal–frontal tracts (i.e., left superior longitudinal and inferior fronto-occipital fasciculi). It was less clear whether white matter alterations persist after recovery from anorexia nervosa. Available data on bulimia nervosa were partially similar to those for anorexia nervosa.

LIMITATIONS

Study sample composition and diffusion tensor imaging analysis techniques were heterogeneous. The number of studies on bulimia nervosa was too limited to be conclusive.

CONCLUSION

White matter microstructure appears to be affected in anorexia nervosa, and these alterations may play a role in the pathophysiology of this eating disorder. Although we found white matter alterations in bulimia nervosa that were similar to those in anorexia nervosa, white matter changes in bulimia nervosa remain poorly investigated, and these findings were less conclusive. Further studies with longitudinal designs and multi-approach analyses are needed to better understand the role of white matter changes in eating disorders.

Alterations in serotonin transporter and body image-related cognition in anorexia nervosa

The serotonin system has been implicated in the pathophysiology of anorexia nervosa (AN). A recent report proposed that body image distortion (BID), a core symptom of AN, may relate to abnormalities of the serotonin system, especially the serotonin transporter (5HTT). Positron emission tomography (PET) studies of underweight patients with active AN reported alterations in serotonin receptors, but not 5HTT. Here, we aimed to disclose the clinicopathophysiology of AN by focusing on 5HTT and cognitive functions, including BID, in groups with active AN. Twenty-two underweight female patients with AN (12 restricting-type AN (ANR); 10 binge-eating/purging-type AN (ANBP)) and 20 age-matched healthy female subjects underwent PET with a 5HTT radioligand [¹¹C]DASB. The binding potential (BP_ND) of [¹¹C]DASB was estimated semiquantitatively, and clinical data from Raven's colored progressive matrices for general intelligence, the Stroop test for focused attention, the Iowa gambling task for decision making and a dot-probe task designed for BID were compared with the levels of BP_ND in different groups. [¹¹C]DASB BP_ND was significantly decreased in the medial parietal cortex in patients with AN and in the dorsal raphe in patients with ANR compared with healthy subjects (p < .05 corrected). Patients with ANR showed a significantly negative correlation between [¹¹C]DASB BP_ND in the dorsal raphe and performance on the dot-probe task (p < .05 corrected). While reduced 5HTT in the medial parietal cortex (the somatosensory association area) is pathophysiologically important in AN in general, additional 5HTT reduction in the dorsal raphe as seen in ANR is implicated for the clinicopathophysiological relevance.

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5HTT decreased in the parietal cortex in patients with AN.

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5HTT decreased in the parietal cortex in patients with ANBP.

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5HTT decreased in the parietal cortex and the dorsal raphe in patients with ANR.

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Patients with AN were poor at responding to the test for body image distortion (BID).

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5HTT in the dorsal raphe was associated with cognitive performance of BID.

Sex Differences in Adolescent Anorexia and Bulimia Nervosa: Beyond the Signs and Symptoms

PURPOSE OF REVIEW

We review research related to sex differences in eating disorders (EDs) in adolescents. Prior work has explored clinical differences; thus, we examine literature in areas identified as playing an etiological or maintenance role in EDs including: genetics, hormones, neurocognitive inefficiencies, and reward circuitry.

RECENT FINDINGS

Sex steroids appear to a play role in the unmasking of genetic risk for development of EDs and puberty may be a heightened period of risk for females. While neurocognitive differences have been well studied in adults with ED, research with adolescents has been less conclusive. Recent work suggests that neural circuitry involved in reward and punishment may play role in development and maintenance of EDs in females. Males are underrepresented in these areas of research. Given known sex differences in healthy adolescents, it is likely there are sex differences in the putative biological etiology/maintenance of EDs. Males should be included in future research.

The potential of calibrated fMRI in the understanding of stress in eating disorders

Eating disorders (ED), including Anorexia Nervosa (AN), Bulimia Nervosa (BN), and Binge Eating Disorder (BED), are medically dangerous psychiatric disorders of unknown etiology. Accumulating evidence supports a biopsychosocial model that includes genetic heritability, neurobiological vulnerability, and psychosocial factors, such as stress, in the development and maintenance of ED. Notably, stress hormones influence appetite and eating, and dysfunction of the physiological stress response has been implicated in ED pathophysiology. Stress signals also appear associated with food reward neurocircuitry response in ED, providing a possible mechanism for the role of stress in appetite dysregulation. This paper provides a review of some of the interacting psychological, behavioral, physiological, and neurobiological mechanisms involved in the stress response among individuals with ED, and discusses novel neuroimaging techniques to address potential physiological confounds of studying neural correlates of stress in ED, such as calibrated fMRI.

A systematic review of reviews of neurocognitive functioning in eating disorders: The state-of-the-literature and future directions

OBJECTIVE

In recent years there has been increasing clinical and empirical interest in neurocognitive functioning in eating disorders (EDs), which has resulted in numerous quantitative and qualitative reviews. However, there has yet to be a comprehensive synthesis or critical review of this literature to identify future directions to advance the field in this area. Therefore the aim of this systematic review of systematic reviews was to (a) characterize the existing literature on neurocognitive functioning in EDs based on recent reviews (i.e., published since 2010), (b) describe related limitations, and (c) suggest avenues for future research to address gaps in the current literature.

METHOD

Electronic databases were queried for reviews of neurocognitive domains (i.e., inhibitory control, decision-making, central coherence, set-shifting, working memory, and attention bias) in EDs, which identified 28 systematic and meta-analytic reviews.

RESULTS

Broadly, the literature indicates deficits across these neurocognitive domains in EDs, though heterogeneity was noted in the magnitude of these effects, which varied to some extent across ED subtypes, sample characteristics, and methodological approaches.

DISCUSSION

While these reviews have generally suggested varying patterns of neurocognitive deficits across EDs, there remain critical limitations regarding the methodological quality of these studies (e.g., the lack of prospective designs, consideration of confounding influences, or examination of interrelationships between neurocognitive domains and relationships between neurocognition and other relevant behavioral constructs). Specifically, we outline 10 key areas that are imperative to address in future research in this area in order to move our field forward.

Anorexia Nervosa, Anxiety, and the Clinical Implications of Rapid Refeeding

The current study aimed to examine the temporal relationship between anxiety symptoms and weight gain for adolescents with anorexia nervosa over the course of an inpatient admission targeting weight restoration through rapid refeeding. Participants were 31 females presenting to a specialist inpatient unit. Psychometric assessments using standardized procedures were conducted to assess co-morbid anxiety diagnoses, and eating disorder symptom severity at admission and discharge. Study protocols were completed on a weekly basis over the course of their admission and were compared with weekly BMI change. Multiple mixed-effects linear models with random intercepts were used to assess change in weight status and psychological variables. Results indicated a reduction in anxiety over the course of hospitalization; however, there was no evidence to support a relationship between anxiety change and weight restoration. The clinical implications of these results are discussed and directions for future research recommended.

Eating Disorders Impact on Vigilance and Decision Making of a Community Sample of Treatment Naive Attention-Deficit/Hyperactivity Disorder Young Adults

Although impulsivity is suggested as a possible link to explain the association of Attention-Deficit/Hyperactivity Disorder (ADHD) with an Eating Disorder (ED), there is little research on how clinical and cognitive/neuropsychological functioning might change when this comorbidity occurs. ADHD individuals are at a higher of developing ED and also obesity. Some research has described the impact of ADHD in clinical treatment-seeking samples of ED patients. Consequently, we investigated how ED impacted on clinical and cognitive variables of a community sample of treatment-naive ADHD individuals. Ninety college students arranged in three groups (ADHD+ED, ADHD only and Controls) were analyzed using semi-structured interviews for ADHD (K-SADS), the Iowa Gambling Task, the Conner's Continuous Performance Test, Digit and Visual span, as well as rating scales for anxiety (STAI), depression (BDI) and impulsivity (BIS-11), and binge eating (BES). We found that ADHD+ED individuals significantly differed from both groups, presenting with a higher body mass index; more hyperactivity-impulsivity symptoms; higher binge eating scores; more omission errors on the Continuous Performance Test; disadvantageous choices on the Iowa Gambling Task. Also, we demonstrated through a moderation/mediation analysis that a greater level of binge eating mediated the increases in body mass index on our sample. There were no significant paths to explain binge-eating severity through changes on any of the neuropsychological tests used. The presence of an ED in normal weight in a community sample of ADHD individuals is associated with higher body mass index and a worse cognitive functioning.

Altered intrinsic functional brain architecture in female patients with bulimia nervosa

BACKGROUND

Bulimia nervosa is a severe psychiatric syndrome with uncertain pathogenesis. Neural systems involved in sensorimotor and visual processing, reward and impulsive control may contribute to the binge eating and purging behaviours characterizing bulimia nervosa. However, little is known about the alterations of functional organization of whole brain networks in individuals with this disorder.

METHODS

We used resting-state functional MRI and graph theory to characterize functional brain networks of unmedicated women with bulimia nervosa and healthy women.

RESULTS

We included 44 unmedicated women with bulimia nervosa and 44 healthy women in our analyses. Women with bulimia nervosa showed increased clustering coefficient and path length compared with control women. The nodal strength in patients with the disorder was higher in the sensorimotor and visual regions as well as the precuneus, but lower in several subcortical regions, such as the hippocampus, parahippocampal gyrus and orbitofrontal cortex. Patients also showed hyperconnectivity primarily involving sensorimotor and unimodal visual association regions, but hypoconnectivity involving subcortical (striatum, thalamus), limbic (amygdala, hippocampus) and paralimbic (orbitofrontal cortex, parahippocampal gyrus) regions. The topological aberrations correlated significantly with scores of bulimia and drive for thinness and with body mass index.

LIMITATIONS

We reruited patients with only acute bulimia nervosa, so it is unclear whether the topological abnormalities comprise vulnerability markers for the disorder developing or the changes associated with illness state.

CONCLUSION

Our findings show altered intrinsic functional brain architecture, specifically abnormal global and local efficiency, as well as nodal- and network-level connectivity across sensorimotor, visual, subcortical and limbic systems in women with bulimia nervosa, suggesting that it is a disorder of dysfunctional integration among large-scale distributed brain regions. These abnormalities contribute to more comprehensive understanding of the neural mechanism underlying pathological eating and body perception in women with bulimia nervosa.

Treatment of anorexia nervosa: a multimethod investigation translating experimental neuroscience into clinical practice

Background

Anorexia nervosa (AN) is a severe psychiatric condition and evidence on how to best treat it is limited.

Objectives

This programme consists of seven integrated work packages (WPs) and aims to develop and test disseminable and cost-effective treatments to optimise management for people with AN across all stages of illness.

Methods

WP1a used surveys, focus groups and a pre–post trial to develop and evaluate a training programme for school staff on eating disorders (EDs). WP1b used a randomised controlled trial (RCT) [International Standard Randomised Controlled Trial Number (ISRCTN) 42594993] to evaluate a prevention programme for EDs in schools. WP2a evaluated an inpatient treatment for AN using case reports, interviews and a quasi-experimental trial. WP2b used a RCT (ISRCTN67720902) to evaluate two outpatient psychological therapies for AN. WP3 used a RCT (ISRCTN06149665) to evaluate an intervention for carers of inpatients with AN. WP4 used actimetry, self-report and endocrine assessment to examine physical activity (PA) in AN. WP5 conducted a RCT (ISRCTN18274621) of an e-mail-guided relapse prevention programme for inpatients with AN. WP6 analysed cohort data to examine the effects of maternal EDs on fertility and their children’s diet and growth. WP7a examined clinical case notes to explore how access to specialist ED services affects care pathways and user experiences. Finally, WP7b used data from this programme and the British Cohort Study (1970) to identify the costs of services used by people with AN and to estimate annual costs of AN for England.

Results

WP1a: a brief training programme improved knowledge, attitudes and confidence of school staff in managing EDs in school. WP1b: a teacher-delivered intervention was feasible and improved risk factors for EDs in adolescent girls. WP2a: both psychological therapies improved outcomes in outpatients with AN similarly, but patients preferred one of the treatments. WP2b: the inpatient treatment (Cognitive Remediation and Emotional Skills Training) was acceptable with perceived benefits by patients, but showed no benefits compared with treatment as usual (TAU). WP3: compared with TAU, the carer intervention improved a range of patient and carer outcomes, including carer burden and patient ED symptomatology. WP4: drive to exercise is tied to ED pathology and a desire to improve mood in AN patients. PA was not increased in these patients. WP5: compared with TAU, the e-mail-guided relapse prevention programme resulted in higher body mass index and lower distress in patients at 12 months after discharge. WP6: women with an ED had impaired fertility and their children had altered dietary and growth patterns compared with the children of women without an ED. WP7a: direct access to specialist ED services was associated with higher referral rates, lower admission rates, greater consistency of care and user satisfaction. WP7b: the annual costs of AN in England are estimated at between £45M and £230M for 2011.

Conclusions

This programme has produced evidence to inform future intervention development and has developed interventions that can be disseminated to improve outcomes for individuals with AN. Directions for future research include RCTs with longer-term outcomes and sufficient power to examine mediators and moderators of change.

Trial registration

Current Controlled Trials ISRCTN42594993, ISRCTN67720902, ISRCTN06149665 and ISRCTN18274621.

Funding

This project was funded by the National Institute for Health Research (NIHR) Programme Grants for Applied Research programme and will be published in full inProgramme Grants for Applied Research; Vol. 5, No. 16. See the NIHR Journals Library website for further project information.

Estrogenic suppression of binge-like eating elicited by cyclic food restriction and frustrative-nonreward stress in female rats

Because binge eating and emotional eating vary through the menstrual cycle in human females, we investigated cyclic changes in binge-like eating in female rats and their control by estrogens. Binge-like eating was elicited by three cycles of 4 days of food restriction and 4 days of free feeding followed by a single frustrative nonreward-stress episode (15 min visual and olfactory exposure to a familiar palatable food) immediately before presentation of the palatable food. Intact rats showed binge-like eating during the diestrous and proestrous phases of the ovarian cycle, but not during the estrous (periovulatory) phase. Ovariectomized (OVX) rats not treated with estradiol (E2) displayed binge-like eating, whereas E2-treated OVX rats did not. The procedure did not increase signs of anxiety in an open-field test. OVX rats not treated with E2 that were subjected to food restriction and sacrificed immediately after frustrative nonreward had increased numbers of cells expressing phosphorylated extracellular signal-regulated kinases (ERK) in the central nucleus of the amygdala (CeA), paraventricular nucleus of hypothalamus (PVN), and dorsal and ventral bed nuclei of the stria terminalis (BNST) compared with nonrestricted or E2-treated rats. These data suggest that this female rat model is appropriate for mechanistic studies of some aspects of menstrual-cycle effects on emotional and binge eating in human females, that anxiety is not a sufficient cause of binge-like eating, and that the PVN, CeA, and BNST may contribute to information processing underlying binge-like eating.

Applying neurobiology to the treatment of adults with anorexia nervosa

BACKGROUND

Anorexia nervosa is a severe, biologically based brain disorder with significant medical complications. It is critical that new, effective treatments are developed to interrupt the persistent course of the illness due to the medical and psychological sequelae. Several psychosocial, behavioral and pharmacologic interventions have been investigated in adult anorexia nervosa; however, evidence shows that their impact is weak and treatment effects are generally small.

METHOD

This paper describes a new neurobiological anorexia nervosa model that shifts focus from solely external influences, such as social and family, to include internal influences that integrate genetic and neurobiological contributions, across the age span. The model serves as a theoretical structure for a new, five-day treatment, outlined in this paper, targeting anorexia nervosa temperament, which integrates neurobiological dimensions into evidence-based treatment interventions. The treatment is in two phases. Phase I is a five day, 40 hour treatment for anorexia nervosa adults. Phase II is the follow-up and is currently being developed.

RESULTS

Preliminary qualitative acceptability data on 37 adults with anorexia nervosa and 60 supports (e.g., spouses, parents, aunts, friends, partners, children of anorexia nervosa adults) are promising from Phase I. Clients with anorexia nervosa and their supports report that learning neurobiological facts improved their understanding of the illness and helped equip them with better tools to manage anorexia nervosa traits and symptoms. In addition, nutritional knowledge changed significantly.

CONCLUSIONS

This is the first neurobiologically based, five-day treatment for adults with anorexia nervosa and their supports. It is a new model that outlines underlying genetic and neurobiological contributions to anorexia nervosa that serves as a foundation to treat both traits and symptoms. Preliminary qualitative findings are promising, with both clients and supports reporting that the neurobiological treatment approach helped them better understand the illness, while better conceptualizing how to respond to their traits and manage their symptoms. Data in Phase I shows promise as a neurobiologically based intervention for anorexia nervosa, and it serves as a foundation for the development of Phase II. Evidence of ongoing program efficacy will be described as data are reported on Phase II.

TRIAL REGISTRATION

NCT NCT02852538 Registered 1 August 2016.

Modulation of Irisin and Physical Activity on Executive Functions in Obesity and Morbid obesity

Whether the executive profile is different between obesity (OB) and morbid obesity (MO) remains unclear. Recent evidence suggests that physical activity (PA) can act as a cognitive enhancer. Irisin is a recently discovered hormone associated with some of the positive effects of PA. The objective of the study was to investigate the executive profile in OB and MO, and to explore the role of PA and irisin. 114 participants were included (21 OB, 44 MO and 49 healthy controls-HC) in the study and assessed with the Wisconsin Card Sorting Test, Stroop Color and Word Test, and Iowa Gambling Task. All participants were female, aged between 18 and 60 years. Results showed a similar dysfunctional profile on decision making in OB and MO compared with HC. Thus, no specific neuropsychological profiles between OB and MO can be clearly observed in our sample. However, a negative correlation was found between irisin and executive functioning. These results demonstrate a specific executive profile in OB and a relevant and negative modulation of irisin on executive functioning. Although irisin might be a promising target for the treatment of obesity, its effects on cognition might be considered when thinking about its therapeutic use.

Neurobiologically informed treatment for adults with anorexia nervosa: a novel approach to a chronic disorder

Anorexia nervosa (AN) is a severe and debilitating disorder with significant medical and psychological sequelae. To date, there are no effective treatments for adults, resulting in high rates of chronicity, morbidity, and mortality. Recent advances in brain imaging research have led to an improved understanding of etiology and specific neurobiological mechanisms underlying symptoms. Despite this, there are no treatments focused on targeting symptoms using this empirically supported mechanistic understanding of the illness. Updated treatment approaches focused on targeting neurobiological mechanisms underlying core AN symptomatology are necessary to improve treatment out-comes for this population. Neurobiologically Enhanced With Family Eating Disorder Trait Response Treatment (NEW FED TR) is a neurobiologically informed treatment targeting key temperament constructs associated with the illness through the delivery of psychoeducation and skills training to patients and nominated carers.

Speaking of That: Terms to Avoid or Reconsider in the Eating Disorders Field

Inspired by an article on 50 terms that, in the interest of clarity in scientific reasoning and communication in psychology, psychiatry, and allied fields, "should be avoided or at most be used sparingly and only with explicit caveats,"(1) we propose a list of terms to avoid or think twice about before using when writing for the International Journal of Eating Disorders (IJED). Drawing upon our experience as reviewers or editors for the IJED, we generated an abridged list of such terms. For each term, we explain why it made our list and what alternatives we recommend. We hope that our list will contribute to improved clarity in scientific thinking about eating disorders, and that it will stimulate discussion of terms that may need to be reconsidered in our field's vocabulary to ensure the use of language that is respectful and sensitive to individuals who experience an eating disorder.

How Does the Brain Implement Adaptive Decision Making to Eat?

Adaptive decision making to eat is crucial for survival, but in anorexia nervosa, the brain persistently supports reduced food intake despite a growing need for energy. How the brain persists in reducing food intake, sometimes even to the point of death and despite the evolution of multiple mechanisms to ensure survival by governing adaptive eating behaviors, remains mysterious. Neural substrates belong to the reward-habit system, which could differ among the eating disorders. The present review provides an overview of neural circuitry of restrictive food choice, binge eating, and the contribution of specific serotonin receptors. One possibility is that restrictive food intake critically engages goal-directed (decision making) systems and "habit," supporting the view that persistent caloric restriction mimics some aspects of addiction to drugs of abuse.

SIGNIFICANCE STATEMENT

An improved understanding of the neural basis of eating disorders is a timely challenge because these disorders can be deadly. Up to 70 million of people in the world suffer from eating disorders. Anorexia nervosa affects 1-4% of women in United States and is the first cause of death among adolescents in Europe. Studies relying on animal models suggest that decision making to eat (or not) can prevail over actual energy requirements due to emotional disturbances resulting in abnormal habitual behavior, mimicking dependence. These recent studies provide a foundation for developing more specific and effective interventions for these disorders.

Functional brain alterations in anorexia nervosa: a scoping review

BACKGROUND

Neuroimaging allows for the identification of brain abnormalities and alterations that are associated with anorexia nervosa (AN). We performed a scoping review to map out the extent and nature of recent research activity on functional magnetic resonance imaging (fMRI) in individuals diagnosed with, or recovered from, AN (AN-REC).

MAIN TEXT

A literature search of PubMed, Psychinfo and Embase was conducted using the search terms "anorexia nervosa" AND "functional magnetic resonance imaging." We included fMRI studies that involved a comparison between individuals with AN or AN-REC and healthy controls published in English language between 2010 and 2015. A total of 49 papers were included, regardless of the experimental stimuli or paradigm.

CONCLUSIONS

Findings varied considerably across studies, reflecting methodological differences in study design, such as sample differences and experimental paradigms. Collectively, studies published during the past five years suggest altered activation in regions related to the fronto-striato and the limbic circuits, which are theorized to have an important role in the pathophysiology of AN.

Reward-related decision making in eating and weight disorders: A systematic review and meta-analysis of the evidence from neuropsychological studies

Eating disorders (EDs) and overweight/obesity (OW/OB) are serious public health concerns that share common neuropsychological features and patterns of disturbed eating. Reward-related decision making as a basic neurocognitive function may trans-diagnostically underlie both pathological overeating and restricted eating. The present meta-analysis synthesizes the evidence from N=82 neuropsychological studies for altered reward-related decision making in all ED subtypes, OW and OB. The overall effect sizes for the differences between currently-ill ED patients and OW/OB people and controls were Hedge's g=-0.49 [CI: -0.63; -0.35], and Hedge's g=-0.39 [CI: -0.53; -0.25], respectively. Decision making was found to be altered to similar degrees in all ED subtypes and OB. Effect sizes, however, diverged for the different measures of decision making. Adolescents appear to be less affected than adults. When foods were used as rewarding stimuli, decision making was found to be intact in OB. The findings support that altered general reward-related decision making is a salient neuropsychological factor across eating and weight disorders in adulthood.

The Practice of Holy Fasting in the Late Middle Ages: A Psychiatric Approach

During the Late Middle Ages, the practice of fasting among religious women in an attempt to follow a pious and ascetic life was common. In this paper, three cases of medieval religious women are described with a particular attention to the figure of St. Catherine of Siena, her life, popularity, and iconography. In the Middle Ages, holy fasting was characterized by a refusal to eat that could involve binging and purging, lack of menstruation, an interest in cooking for others, and in some cases death due to inanition. In the Medieval narratives of fasting holy women, we can see patterns that are compatible with symptoms of anorexia nervosa. From a psychiatric perspective, it is possible to elucidate and understand the practice of fasting among religious people in the Late Middle Ages.

Dimensions of emotion dysregulation in anorexia nervosa and bulimia nervosa: A conceptual review of the empirical literature

Several existing conceptual models and psychological interventions address or emphasize the role of emotion dysregulation in eating disorders. The current article uses Gratz and Roemer's (2004) multidimensional model of emotion regulation and dysregulation as a clinically relevant framework to review the extant literature on emotion dysregulation in anorexia nervosa (AN) and bulimia nervosa (BN). Specifically, the dimensions reviewed include: (1) the flexible use of adaptive and situationally appropriate strategies to modulate the duration and/or intensity of emotional responses, (2) the ability to successfully inhibit impulsive behavior and maintain goal-directed behavior in the context of emotional distress, (3) awareness, clarity, and acceptance of emotional states, and (4) the willingness to experience emotional distress in the pursuit of meaningful activities. The current review suggests that both AN and BN are characterized by broad emotion regulation deficits, with difficulties in emotion regulation across the four dimensions found to characterize both AN and BN, although a small number of more specific difficulties may distinguish the two disorders. The review concludes with a discussion of the clinical implications of the findings, as well as a summary of limitations of the existing empirical literature and suggestions for future research.

Application of the Research Domain Criteria (RDoC) framework to eating disorders: emerging concepts and research

The Research Domain Criteria (RDoC) project was initiated by the National Institute of Mental Health as a heuristic for addressing the limitations of categorical, symptom-based psychiatric diagnoses. RDoC is conceptualized as a matrix, with the rows representing dimensional constructs or domains implicated in the expression of psychiatric symptoms and the columns representing units of analysis that can be used to assess dimensional constructs (i.e., genes, molecules, cells, circuits, physiology, behavior, and self-reports). Few studies in eating disorders have adopted an RDoC framework, but accumulating data provide support for the relevance of RDoC dimensions to eating disorder symptoms. Herein, we review findings from RDoC-informed studies across the five domains of functioning included in the RDoC matrix-negative valence systems, positive valence systems, cognitive systems, systems for social processes, and arousal and regulatory systems-and describe directions for future research utilizing RDoC to enhance study design and treatment development in eating disorders.

Recent advances in neuroimaging to model eating disorder neurobiology

The eating disorders (EDs) anorexia nervosa (AN), bulimia nervosa (BN), and binge eating disorder (BED) are severe psychiatric disorders with high mortality. There are many symptoms, such as food restriction, episodic binge eating, purging, or excessive exercise that are either overlapping or lie on opposite ends of a scale or spectrum across those disorders. Identifying how specific ED behaviors are linked to particular neurobiological mechanisms could help better categorize ED subgroups and develop specific treatments. This review provides support from recent brain imaging research that brain structure and function measures can be linked to disorder-specific biological or behavioral variables, which may help distinguish ED subgroups, or find commonalities between them. Brain structure and function may therefore be suitable research targets to further study the relationship between dimensions of behavior and brain function relevant to EDs and beyond the categorical AN, BN, and BED distinctions.

Does anxiety improve during weight restoration in anorexia nervosa? A systematic review

Weight restoration is considered a principal outcome for treatment of Anorexia Nervosa (AN) due to the significant physiological disturbances resultant from acute states of malnutrition. Treatment outcomes for populations with AN are relatively poor, with increasing evidence suggesting that weight restoration alone is insufficient for long-term recovery. Research aimed at understanding the psychological sequaele of AN, in particular during weight restoration, nevertheless remain scarce. This systematic review aimed to evaluate existing research regarding anxiety symptoms during treatment for AN, and the relationship of anxiety symptomology and weight restoration. Twelve articles were identified from a systematic search of three electronic databases (PsycINFO, MEDLINE, and Web of Science), and were eligible for inclusion. Study methodology, results and quality were reviewed. Results regarding change in anxiety symptomology were inconsistent, though evidence did not support a relationship between anxiety change and weight restoration. Reasons for these inconsistencies and limitations of included studies were reviewed. Further research is warranted to elucidate the role of anxiety in AN and its implications for treatment and longer-term outcome.

Alterations in Activity, Volume, and Connectivity of Body-Processing Brain Areas in Anorexia Nervosa

Body image disturbance is one of the main symptoms of eating disorders; however, the neural basis of this phenomenon is not well understood yet. In the present paper, we review studies investigating the neuronal correlates of visual body perception in anorexia nervosa. We first focus on the well-known parietal lobe contribution to body image processing and its malfunction. Additionally, we focus on the contribution and involvement of the extrastriate and fusiform body area in eating disorders, especially anorexia nervosa. The summarized studies provide first evidence for a reduced activity, volume, and connectivity in brain areas involved and specialized in the visual processing of human bodies. In general, the reviewed studies provide evidence for abnormalities in body-processing brain areas in anorexia nervosa, indicating two structures in the brain that are involved: early stages of body processing in the visual extrastriate cortex and later stages in the parietal cortex.

Are Extremes of Consumption in Eating Disorders Related to an Altered Balance between Reward and Inhibition?

The primary defining characteristic of a diagnosis of an eating disorder (ED) is the "disturbance of eating or eating-related behavior that results in the altered consumption or absorption of food" (DSM V; American Psychiatric Association, 2013). There is a spectrum, ranging from those who severely restrict eating and become emaciated on one end to those who binge and overconsume, usually accompanied by some form of compensatory behaviors, on the other. How can we understand reasons for such extremes of food consummatory behaviors? Recent work on obesity and substance use disorders has identified behaviors and neural pathways that play a powerful role in human consummatory behaviors. That is, corticostriatal limbic and dorsal cognitive neural circuitry can make drugs and food rewarding, but also engage self-control mechanisms that may inhibit their use. Importantly, there is considerable evidence that alterations of these systems also occur in ED. This paper explores the hypothesis that an altered balance of reward and inhibition contributes to altered extremes of response to salient stimuli, such as food. We will review recent studies that show altered sensitivity to reward and punishment in ED, with evidence of altered activity in corticostriatal and insula processes with respect to monetary gains or losses, and tastes of palatable foods. We will also discuss evidence for a spectrum of extremes of inhibition and dysregulation behaviors in ED supported by studies suggesting that this is related to top-down self-control mechanisms. The lack of a mechanistic understanding of ED has thwarted efforts for evidence-based approaches to develop interventions. Understanding how ED behavior is encoded in neural circuits would provide a foundation for developing more specific and effective treatment approaches.

Eating disorders in children and adolescents: state of the art review

Despite their high prevalence, associated morbidity and mortality, and available treatment options, eating disorders (EDs) continue to be underdiagnosed by pediatric professionals. Many adolescents go untreated, do not recover, or reach only partial recovery. Higher rates of EDs are seen now in younger children, boys, and minority groups; EDs are increasingly recognized in patients with previous histories of obesity. Medical complications are common in both full and subthreshold EDs and affect every organ system. No single cause of EDs has emerged, although neurobiological and genetic predispositions are emerging as important. Recent treatment paradigms acknowledge that they are not caused by families or chosen by patients. EDs present differently in pediatric populations, and providers should have a high index of suspicion using new Diagnostic and Statistical Manual, 5th edition diagnostic criteria because early intervention can affect prognosis. Outpatient family-based treatment focused on weight restoration, reducing blame, and empowering caregivers has emerged as particularly effective; cognitive behavioral therapy, individual therapy, and higher levels of care may also be appropriate. Pharmacotherapy is useful in specific contexts. Full weight restoration is critical, often involves high-calorie diets, and must allow for continued growth and development; weight maintenance is typically inappropriate in pediatric populations. Physical, nutritional, behavioral, and psychological health are all metrics of a full recovery, and pediatric EDs have a good prognosis with appropriate care. ED prevention efforts should work toward aligning with families and understanding the impact of antiobesity efforts. Primary care providers can be key players in treatment success.

Social insecurity in relation to orbitofrontal activity in patients with eating disorders: a near-infrared spectroscopy study

BACKGROUND

Functional neuroimaging techniques are widely used to elucidate changes in brain activity, and various questionnaires are used to investigate psychopathological features in patients with eating disorders (ED). It is well known that social skills and interpersonal difficulties are strongly associated with the psychopathology of patients with ED. However, few studies have examined the association between brain activity and social relationships in patients with ED, particularly in patients with extremely low body weight.

METHODS

In this study, 22-channel near-infrared spectroscopy was used to quantify regional hemodynamic changes during a letter fluency task (LFT) in 20 female patients with ED with a mean body mass index of 14.0 kg/m(2) and 31 female controls (CTLs). Symptoms were assessed using the Eating Disorder Inventory-2 and Beck Depression Inventory. We hypothesized that frontal activity in patients with ED would be lower than in CTLs and would show different correlations with psychopathological features compared with CTLs.

RESULTS

The LFT performance and score on the social insecurity subscale of the Eating Disorder Inventory-2 were significantly higher in the ED group than in the CTL group. The mean change in oxygenated hemoglobin (oxy-Hb) in bilateral frontal regions during the LFT was significantly smaller in the ED group than in the CTL group. Social insecurity score was positively correlated with the concentration of oxy-Hb in the bilateral orbitofrontal cortex in the ED group but not in the CTL group.

CONCLUSIONS

These results suggest that activity of the orbitofrontal cortex is associated with social insecurity and disturbed in patients with ED. Therefore, disturbed orbitofrontal cortex activity may underlie the lack of insight and social isolation that is characteristic of patients with ED.

Anorexia nervosa and bulimia nervosa: brains, bones and breeding

Recent research has modified both the conceptualization and treatment of eating disorders. New diagnostic criteria reducing the "not otherwise specified" category should facilitate the early recognition and treatment of anorexia nervosa (AN) and bulimia nervosa (BN). Technology-based studies identify AN and BN as "brain circuit" disorders; epidemiologic studies reveal that the narrow racial, ethnic and income profile of individuals no longer holds true for AN. The major organs affected long term-the brain and skeletal system-both respond to improved nutrition, with maintenance of body weight the best predictor of recovery. Twin studies have revealed gene x environment interactions, including both the external (social) and internal (pubertal) environments of boys and of girls. Family-based treatment has the best evidence base for effectiveness for younger patients. Medication plays a limited role in AN, but a major role in BN. Across diagnoses, the most important medicine is food.

A physiological perspective on the neuroscience of eating

I present the thesis that 'being physiological,' i.e., analyzing eating under conditions that do not perturb, or minimally perturb, the organism's endogenous processes, should be a central goal of the neuroscience of eating. I describe my understanding of 'being physiological' based on [i] the central neural-network heuristic of CNS function that traces back to Cajal and Sherrington, [ii] research on one of the simpler problems in the neuroscience of eating, identification of endocrine signals that control eating. In this context I consider natural meals, physiological doses and ranges, and antagonist studies. Several examples involve CCK. Next I describe my view of the cutting edge in the molecular neuroscience of eating as it has evolved from the discovery of leptin signaling through the application of optogenetic and pharmacogenetic methods. Finally I describe some novel approaches that may advance the neuroscience of eating in the foreseeable future. I conclude that [i] the neuroscience of eating may soon be able to discern 'physiological' function in the operation of CNS networks mediating eating, [ii] the neuroscience of eating should capitalize on methods developed in other areas of neuroscience, e.g., improved methods to record and manipulate CNS function in behaving animals, identification of canonical regional circuits, use of population electrophysiology, etc., and [iii] subjective aspects of eating are crucial aspects of eating science, but remain beyond mechanistic understanding.

A systematic review of the effects of neuromodulation on eating and body weight: evidence from human and animal studies

BACKGROUND

Eating disorders (ED) are chronic and sometimes deadly illnesses. Existing treatments have limited proven efficacy, especially in the case of adults with anorexia nervosa (AN). Emerging neural models of ED provide a rationale for more targeted, brain-directed interventions.

AIMS

This systematic review has examined the effects of neuromodulation techniques on eating behaviours and body weight and assessed their potential for therapeutic use in ED.

METHOD

All articles in PubMed, PsychInfo and Web of Knowledge were considered and screened against a priori inclusion/exclusion criteria. The effects of repetitive transcranial magnetic stimulation (rTMS), transcranial direct current stimulation, vagus nerve stimulation (VNS) and deep brain stimulation (DBS) were examined across studies in ED samples, other psychiatric and neurological disorders, and animal models.

RESULTS

Sixty studies were identified. There is evidence for ED symptom reduction following rTMS and DBS in both AN and bulimia nervosa. Findings from studies of other psychiatric and neurological disorders and from animal studies demonstrate that increases in food intake and body weight can be achieved following DBS and that VNS has potential value as a means of controlling eating and inducing weight loss.

CONCLUSIONS

Neuromodulation tools have potential for reducing ED symptomatology and related behaviours, and for altering food intake and body weight. In response to such findings, and emerging neural models of ED, treatment approaches are highly unlikely to remain 'brainless'. More research is required to evaluate the potential of neuromodulation procedures for improving long-term outcomes in ED.

Sex differences in the physiology of eating

Hypothalamic-pituitary-gonadal (HPG) axis function fundamentally affects the physiology of eating. We review sex differences in the physiological and pathophysiological controls of amounts eaten in rats, mice, monkeys, and humans. These controls result from interactions among genetic effects, organizational effects of reproductive hormones (i.e., permanent early developmental effects), and activational effects of these hormones (i.e., effects dependent on hormone levels). Male-female sex differences in the physiology of eating involve both organizational and activational effects of androgens and estrogens. An activational effect of estrogens decreases eating 1) during the periovulatory period of the ovarian cycle in rats, mice, monkeys, and women and 2) tonically between puberty and reproductive senescence or ovariectomy in rats and monkeys, sometimes in mice, and possibly in women. Estrogens acting on estrogen receptor-α (ERα) in the caudal medial nucleus of the solitary tract appear to mediate these effects in rats. Androgens, prolactin, and other reproductive hormones also affect eating in rats. Sex differences in eating are mediated by alterations in orosensory capacity and hedonics, gastric mechanoreception, ghrelin, CCK, glucagon-like peptide-1 (GLP-1), glucagon, insulin, amylin, apolipoprotein A-IV, fatty-acid oxidation, and leptin. The control of eating by central neurochemical signaling via serotonin, MSH, neuropeptide Y, Agouti-related peptide (AgRP), melanin-concentrating hormone, and dopamine is modulated by HPG function. Finally, sex differences in the physiology of eating may contribute to human obesity, anorexia nervosa, and binge eating. The variety and physiological importance of what has been learned so far warrant intensifying basic, translational, and clinical research on sex differences in eating.

A double-blind, randomized pilot trial of chromium picolinate for binge eating disorder: results of the Binge Eating and Chromium (BEACh) study

OBJECTIVE

Chromium treatment has been shown to improve mood, appetite, and glucose regulation in various psychiatric and medical patient populations. The authors propose that chromium may be useful in the treatment of binge eating disorder (BED).

METHOD

Twenty-four overweight adults with BED were enrolled in a 6-month double-blind placebo-controlled trial and randomly assigned to receive either 1000mcg chromium/day ("high dose"; n=8) or 600mcg chromium/day ("moderate dose"; n=9) as chromium picolinate or placebo (n=7). Mixed linear regression models were used to estimate mean change in binge frequency and related psychopathology, weight, symptoms of depression, and fasting glucose.

RESULTS

Fasting glucose was significantly reduced in both chromium groups compared to the placebo group; similarly, numerically, but not significantly, greater reductions in binge frequency, weight, and symptoms of depression were observed in those treated with chromium versus placebo, although statistical power was limited in this pilot trial. For fasting glucose, the findings suggest a dose response with larger effects in the high dose compared to moderate dose group.

CONCLUSION

These initial findings support further larger trials to determine chromium's efficacy in maintaining normal glucose regulation, reducing binge eating and related psychopathology, promoting modest weight loss, and reducing symptoms of depression in individuals with BED. Studies designed to link the clinical effects of chromium with changes in underlying insulin, serotonin, and dopamine pathways may be especially informative. If efficacious, chromium supplementation may provide a useful, low-cost alternative to or augmentation strategy for selective serotonin reuptake inhibitors, which have partial efficacy in BED. ClinicalTrials.gov NCT00904306.

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.