Neuropsychological function in patients with anorexia nervosa or bulimia nervosa

Associations between disordered eating, internalizing symptoms, and behavioral and neural correlates of response inhibition in preadolescence

Response inhibition difficulties are reported in individuals with eating disorders (EDs), anxiety, and depression. Although ED symptoms and internalizing symptoms co-occur in preadolescence, there is limited research examining associations between these symptoms and response inhibition in this age group. This study is the first to investigate the associations between behavioral and neural markers of response inhibition, disordered eating (DE), and internalizing symptoms in a community sample of preadolescents. Forty-eight children (M age = 10.95 years, 56.3% male) completed a Go/NoGo task, whereas electroencephalography was recorded. Self-report measures of DE and internalizing symptoms were collected. Higher levels of anxiety and depression were associated with neural markers of suboptimal response inhibition (attenuated P3NoGo amplitudes) in preadolescence. In contrast, higher levels of depression were associated with greater response inhibition at a behavioral level. These findings suggest internalizing symptoms in preadolescence are associated with P3-indexed difficulties in evaluation and monitoring, but these are not sufficient to disrupt behavioral performance on a response inhibition task. This pattern may reflect engagement of compensatory processes to support task performance. DE was not significantly associated with response inhibition, suggesting that difficulties in response inhibition may only be reliably observed in more chronic and severe DE and ED presentations.

[Medical complications in anorexia and bulimia nervosa]

Anorexia nervosa and bulimia nervosa are eating disorders associated with life-threatening multisystemic medical complications. This narrative review aimed to present the medical complications most related to these disorders. In anorexia nervosa, many of them are linked to malnutrition and underweight, usually reversible with renutrition and weight restoration, although refeeding can also be linked to some medical complications. Purging behaviors observed in the anorexia nervosa binge-purging subtype and bulimia nervosa have been mainly related to hydrolectrolyte and acid-base disturbances, in addition to local complications. Thus, an early identification and therapeutic intervention of these disorders is considered crucial. Integral medical monitoring should be ensured to prevent potential serious complications from the early stages, with the involvement of physicians, psychologists, nutritionists, and other specialists in a multidisciplinary approach according to the patient's needs.

Verbal memory following weight gain in adult patients with anorexia nervosa: A longitudinal study

BACKGROUND

Patients with Anorexia Nervosa (AN) show a moderate deficit in overall neuropsychological functioning. Since previous studies on memory performance mainly employed cross-sectional designs, the present study aims to investigate changes in verbal memory following weight-gain.

METHODS

Verbal memory was assessed with the Wechsler Memory Scale-Revised (WMS-R; 'logical memory'-story-recall-subtest) and the California Verbal Learning Test-II (CVLT-II; 'verbal learning'). Included were 31 female patients with AN (18 restricting-, 13 purging-subtype; average disease duration: 5.1 years; average baseline BMI: 14.4 kg/m² ) and 24 medication-free normal-weight healthy women adjusted for age at baseline (T0). In a post-treatment assessment of approx. 6 weeks with weight increase (T1), 18 patients with AN and 20 healthy women were assessed again. Group differences in verbal memory (i.e., WMS-R, CVLT-II) were assessed for the baseline comparisons with a multivariate ANOVA and longitudinal data were analysed with repeated measures (RM) ANOVAs.

RESULTS

At baseline, patients with AN as compared to healthy women displayed deficits in logical memory. In the follow-up assessment, patients with AN improved their logical memory significantly compared to healthy controls (p < 0.006). Furthermore, groups did not differ in verbal learning neither before nor after inpatient treatment.

CONCLUSIONS

Enhanced logical memory in patients with AN following weight-gain is probably due to the impaired memory as compared to healthy controls at T0. A survivorship bias could explain the improved memory performance in longitudinal data in contrast to cross-sectional studies. Patients with AN with poorer memory performance before inpatient treatment are at higher risk to drop out and need support.

Clinical and Ethical Dilemmas in the Involuntary Treatment of Anorexia Nervosa

LEARNING OBJECTIVES

After completing this activity, practitioners will be better able to:• Discuss the growing body literature emphasizing moderation and harm-reduction in patients with severe and enduring anorexia nervosa (SE-AN)• Outline and discuss the legal, ethical, and medical challenges inpatient providers face when treating patients with SE-AN.

ABSTRACT

Patients with severe and enduring anorexia nervosa (SE-AN) present numerous clinical and ethical challenges for the hospital psychiatrist. Patients typically come to the hospital in a state of severe medical compromise. Common difficulties in the period of acute medical stabilization include assessment of decision-making capacity and the right to decline treatment, as well as legally complex decisions pertaining to administering artificial nutrition over the patient's objection. Following acute medical stabilization, the psychiatric consultant must decide whether psychiatric hospitalization for continued treatment is indicated, and if so, whether involuntary hospitalization is indicated. The standard of care in these situations is unclear. Pragmatic issues such as lack of appropriate facilities for specialized treatment are common. If involuntary hospitalization is not approved or not pursued, there may be difficulty in determining whether, when, and how to involve palliative care consultants to guide further management. These cases are complex and largely reside in a medico-legal and ethical gray area. This article discusses the difficulties associated with these cases and supports a growing body of literature emphasizing moderation and harm-reduction in patients with SE-AN. Physician-assisted dying (PAD) is also discussed.

Cognitive and clinical gender‐related differences among binge‐spectrum eating disorders: Analysis of therapy response predictors

OBJECTIVE

This study assessed gender-related differences in executive functions (decision-making, inhibitory control and cognitive flexibility), personality traits and psychopathological symptoms in binge-spectrum eating disorders (EDs). Secondly, we aimed to separately explore the predictive value of gender and executive functions in treatment outcome.

METHOD

A battery of self-reported and neurocognitive measures were answered by a sample of 85 patients (64 females) diagnosed with a binge-spectrum ED (41 BN; 44 binge eating disorder).

RESULTS

Data showed gender-related differences in executive functioning, displaying women lower inhibitory control and lower cognitive flexibility than men. Regarding personality traits and psychopathology symptoms, women presented higher reward dependence and cooperativeness, as well as more drive for thinness, body dissatisfaction, bulimia, and somatisation symptoms than men. Finally, worse executive functioning, particularly having lower ability in concept formation seems to predict worse treatment outcomes and dropout in these patients.

CONCLUSIONS

We described gender specific neuropsychological, personality and psychopathological impairments in patients with binge-spectrum EDs. Moreover, difficulties in executive functioning might have an impact on treatment response, since patients with a lower ability in concept formation are less likely to benefit from treatment. The present results can help improving current treatment approaches by tackling gender and individual differences.

Evaluating thinking styles in adults with an eating disorder: Associations with life satisfaction, psychological symptoms, and treatment engagement

Cognitive weaknesses have been implicated as a vulnerability factor in the development and maintenance of eating disorders. Despite this, cognitive styles are not routinely assessed in adult outpatient eating disorder programs and little is known about how they may impact patients' functional outcomes, psychological symptoms, or treatment engagement. The aim of this study was to evaluate thinking styles (i.e., cognitive rigidity and attention to detail) among adults attending specialized outpatient treatment for an eating disorder and assess whether such styles were associated with participants' satisfaction with life, psychological symptoms, and engagement in the outpatient group therapy program. Demographic and physical health information was collected from 95 adults who were eligible for an outpatient program. Participants completed the Detail and Flexibility Questionnaire, Satisfaction with Life Scale, Beck Depression Inventory second edition, and Beck Anxiety Inventory. Elevated scores for cognitive rigidity and attention to detail were transdiagnostic rather than specific to eating disorder diagnoses. Cognitive rigidity and attention to detail were associated with lower satisfaction with life, and increased anxiety and depression. Cognitive styles of cognitive rigidity and attention to detail were not associated with engagement in treatment or treatment completion. Cognitive patterns may be important for clinicians to evaluate as part of routine outpatient care given that they occur transdiagnostically and are linked with psychological symptoms and functional outcomes for adults struggling with an eating disorder.

Orthorexia nervosa and executive dysfunction: symptomatology is related to difficulties with behavioral regulation

PURPOSE

This research explored whether orthorexia nervosa is associated with deficits in executive function.

METHODS

A non-clinical sample of participants (n = 405; 80% women, 53% white, mean age = 24, mean body mass index = 25) completed the Orthorexia Nervosa Inventory (ONI) and the Behavior Rating Inventory of Executive Function-Adult version (BRIEF-A).

RESULTS

ONI scores were weakly to moderately correlated with all BRIEF-A scales (p < 0.001 for eight scales, p < 0.05 for one scale), exhibiting the greatest correlations with the scales assessing behavioral regulation: Emotional Control (r = 0.34), Inhibition (r = 0.30), Set Shifting (r = 0.25), and Self-Monitoring (r = 0.28). Hierarchical regression analyses revealed that eight of these nine relationships remained significant (p < 0.001 for five scales including all behavioral regulation scales, p < 0.01 for two scales, p < 0.05 for one scale) after controlling for demographic variables (e.g., gender, body mass index, age, education level) and diagnoses of an eating disorder, obsessive-compulsive disorder, attention deficit/hyperactivity disorder, autism, and learning disability.

CONCLUSION

These findings suggest that, despite unique manifestations, orthorexia and anorexia may possess an overlapping neuropsychological profile marked by deficits in executive function, which may negatively impact daily life.

LEVEL OF EVIDENCE

Level V, descriptive cross-sectional study.

Specific Learning Disorders and Eating Disorders: an Italian retrospective study

BACKGROUND

Although Anorexia Nervosa (AN) patients show dysfunctional behaviour in information processing, visual and verbal memory performance, and different cognitive fields, regardless of their BMI, the literature on the correlations between Eating Disorders (ED) and Neurodevelopmental Disorders (NDD) does not provide conclusive data. Rather than a consequence of the mental disorder, cognitive dysfunctions may be a risk factor for AN.

METHODS

Our retrospective study investigates the prevalence of Specific Learning Disorder (SLD) among patients with ED. We considered 262 patients being treated at the Emilia Romagna Feeding and Eating Disorders Outpatient Service in Bologna, Italy. We compared the results with the Italian reference values, according to the most recent data provided by the Italian Ministry of Education.

RESULTS

We found that 25 patients out of 262 (9.54%) presented a comorbid diagnosis of SLD. This SLD prevalence is higher than the Italian reference values (4.9% in the school year 2018/19, p < 0.001). Comorbidity with SLD was significantly more frequent in males. A diagnosis of SLD was not associated with a higher frequency of any specific ED diagnosis or with psychiatric comorbidity in general. Positive family history for SLD was not significantly associated with either a positive family history for ED or a diagnosis of SLD.

CONCLUSIONS

This is the first Italian study to investigate the prevalence of SLD in ED patients during childhood and adolescence. Our data support previous research documenting that neuropsychological deficit could lead to the development of ED.

Neural Correlates of Executive Functioning in Anorexia Nervosa and Obsessive-Compulsive Disorder

Anorexia nervosa (AN) and obsessive-compulsive disorder (OCD) are commonly reported to co-occur and present with overlapping symptomatology. Executive functioning difficulties have been implicated in both mental health conditions. However, studies directly comparing these functions in AN and OCD are extremely limited. This review provides a synthesis of behavioral and neuroimaging research examining executive functioning in AN and OCD to bridge this gap in knowledge. We outline the similarities and differences in behavioral and neuroimaging findings between AN and OCD, focusing on set shifting, working memory, response inhibition, and response monitoring. This review aims to facilitate understanding of transdiagnostic correlates of executive functioning and highlights important considerations for future research. We also discuss the importance of examining both behavioral and neural markers when studying transdiagnostic correlates of executive functions.

Association of executive function problems and disordered eating behaviours in teens with type 1 diabetes

AIM

To explore cross-sectional associations between executive function problems and disordered eating behaviours in teens with type 1 diabetes.

METHODS

Executive function was assessed by the Behavior Rating Inventory of Executive Function (BRIEF), self-report and parent proxy-report versions. Scores ≥60 (on Global Executive Composite, Behavioral Regulation Index, Metacognition Index or clinical scales) indicated problems with executive function. Disordered eating behaviour was assessed by the Diabetes Eating Problem Survey Revised (DEPS-R) and categorized as follows: <10 low, 10-19 moderate and ≥20 high.

RESULTS

In the 169 teens (46% girls, median age 16.0 years [range 13.7-18.7], median diabetes duration 8.9 years [range 1.4-16.6]), 29% had moderate and 12% had high level of disordered eating behaviours. Executive function problems were present in 9% by self report and 26% by parent proxy-report. Among teens with moderate/high level of disordered eating behaviours, 19% had executive function problems by self report (vs. 2% of teens with low level of disordered eating behaviours, p < 0.001) and 33% had executive function problems by parent proxy-report (vs. 20% of teens with low level of disordered eating behaviours, p = 0.056). A greater level of disordered eating behaviours was associated with executive function problems by teen self report on the General Executive Composite (p < 0.001), Behavioral Regulation Index (p < 0.001), emotional control clinical scale (p < 0.001), shift clinical scale (p < 0.001) and by parent proxy-report on the task initiation clinical scale (p = 0.008).

CONCLUSIONS

Assessing executive function and screening for disordered eating behaviours in teens with type 1 diabetes could help identify a subset of teens at high risk for adverse outcomes and need for intervention.

Neuropsychological functioning in adult anorexia nervosa: A meta-analysis

Several studies have conceptualized neuropsychological dysfunction as part of the core pathology and defining behaviors seen in the eating disorder anorexia nervosa (AN). The aim of the current review was to synthesize the differences in neuropsychological test performance between individuals with AN and healthy controls, quantify and explain their heterogeneity. The search and screening procedures resulted in fifty studies that comprised 186 neuropsychological test results. Utilizing random-effects meta-analyses, the results revealed evidence for significant, moderate underperformance in people with AN in overall neuropsychological functioning (g¯ = -0.43, 95 % CI [-0.50, -0.36]). Weighted mean effect sizes ranged from g¯ = -0.53 for visuospatial abilities to g¯ = -0.10 for planning. Study and participant characteristics, including body mass index (BMI) and age, had significant moderator effects, especially on executive function, memory, and visuospatial abilities. The findings from the current study provide an extensive and comprehensive overview of the possible impairments in neuropsychological functioning in adult patients diagnosed with AN.

Effects of cognitive-behavioral and psychodynamic-interpersonal treatments for eating disorders: a meta-analytic inquiry into the role of patient characteristics and change in eating disorder-specific and general psychopathology in remission

BACKGROUND

Cognitive behavior therapy (CBT) and psychodynamic-interpersonal therapies (PIT) are two widely used and conceptually different outpatient treatments for eating disorders (EDs). To better understand how these treatments works, for whom, and under what circumstances, there is a need for knowledge about how outcomes are affected by diagnosis, comorbidity, changes in psychopathology, and study design.

METHOD

Reports on the effects of CBT and PIT for eating disorders were searched. Rates of remission and changes in ED specific- and general psychopathology were computed. Regression models were made to predict event rates by changes in specific- and general psychopathology, as well as ED diagnosis and study design.

RESULTS

The remission rate of CBT for binge eating disorder was 50%, significantly higher than the effect for other diagnostic groups (anorexia = 33%, bulimia: 28%, mixed samples 30%). The number of studies found for PIT was limited. All effect sizes differed from zero (binge eating disorder = 27%, anorexia = 24%, bulimia = 18%, mixed samples = 15%), but the precision of the estimates was low, with some lower-bound confidence intervals close to zero. For CBT, change in ED specific psychopathology predicted remission only when controlling for ED diagnosis, while change in general psychopathology did not predict remission at all. The predictive value of change in psychopathology for PIT, and the potential impact of comorbid personality disorders could not be analyzed due to a lack of studies. There was no difference in effects between randomized controlled trials and observational studies.

CONCLUSIONS

CBT showed consistent remission rates for all EDs but left a substantial number of patients not in remission. Extant evidence suggest that PIT is not consistently effective in achieving remission for patients with EDs, although this finding is uncertain due to a small number of eligible studies. A group of patients with eating disorders may, however, require therapy aimed at strengthening deficits in self functions not easily ameliorable by cognitive behavioral techniques alone. Further research should be aimed at identifying treatment interventions that helps patients change behavior, while strengthening self-functions to substitute eating-disordered behavior in the long-term.

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.

Naturalistic and Uncontrolled Pilot Study on the Efficacy of Vortioxetine in Binge Eating Disorder With Comorbid Depression

Background: Binge eating disorder (BED) is clinically relevant by virtue of the global impairment, poor quality of life, and increased overall medical morbidity. The high comorbidity with psychiatric disorders, particularly depression, has received attention as a possible mediator of the poor outcome. Further, BED and depression share cognitive dysfunctions. This naturalistic and uncontrolled pilot study aimed at evaluating the efficacy of vortioxetine (VTX) on depressive symptoms in patients with BED, secondly the efficacy in improving a broad array of executive functions, and third to explore the effect on eating behavior and body weight. Methods: This pilot study involved 30 patients with BED and comorbid MDD, treated with VTX for 24 weeks. Assessments were run at baseline (t 0), 4 (t 1), 8 (t 2), 12 (t 3), and 24 (t 4) weeks. Changes in depressive symptoms (HDRS and BDI), executive functions, eating behaviors (binge frequency and severity, night eating, food addiction), and body weight were estimated after treatment with VTX through GLM. Results: Significant improvements emerged after treatment with VTX in: depression (HDRS p < 0.001; BDI p = 0.002) regardless the dose of VTX and first diagnosis (BED/MDD), working memory (RAVLT acquisition p = 0.01, delay recall p < 0.001, RCFT percentage of recall p = 0.01, and Attentional Matrices p = 0.05), binge days frequency (p < 0.001), binge eating severity (BES p < 0.001), night eating (p = 0.001), food addiction (YFAS 2.0 p = 0.039), and body weight (p = 0.039). The improvement in depressive symptoms was associated with the concurrent improvement in night eating as assessed by the I-NEQ. Conclusions: VTX can be a valid therapeutic choice for patients with BED with comorbid depression in controlling the depressive symptoms, working memory, and eating behavior. Indeed, by acting on affective symptoms, neurocognitive functioning, and eating behaviors, it confirms the results already obtained with VTX in other disorders, expanding them to BED.

Cognitive Function in Adults with Enduring Anorexia Nervosa

Anorexia Nervosa (AN) is a severe and often enduring disorder characterized by restriction of food intake, low body weight, fear of weight gain, and distorted body image. Investigations on cognition performance in AN patients have yielded conflicting results. Using an established and sensitive computerized cognitive test battery, we aimed to assess core aspects of cognitive function, including attention span, information processing, reasoning, working and episodic memory, in AN patients and controls. Patients were recruited from the Danish Prospective Longitudinal all-comer inclusion study in Eating Disorders (PROLED). Included were 26 individuals with AN and 36 healthy volunteers (HV). All were tested with CogTrack (an online cognitive assessment system) at baseline, and AN patients were tested again at a follow-up time point after weight increase (n = 13). At baseline, AN patients showed faster reaction times in the attention tasks, as well as increased accuracy in grammatical reasoning compared to HV. There were no differences in cognitive function between AN patients and HV in the other cognitive domains measured (sustained attention, working and episodic memory, speed of retrieval, and speed of grammatical reasoning). No differences were visible in the AN sample between baseline and follow-up. Performance did not correlate with any clinical variables in the AN sample. These findings supplement results from other studies suggesting increased concentration and reasoning accuracy in patients suffering from AN, who showed increased performance in cognitive tasks despite their illness.

Differential longitudinal changes of neuronal and glial damage markers in anorexia nervosa after partial weight restoration

Atrophic brain changes in acute anorexia nervosa (AN) are often visible to the naked eye on computed tomography or magnetic resonance imaging scans, but it remains unclear what is driving these effects. In neurological diseases, neurofilament light (NF-L) and tau protein have been linked to axonal damage. Glial fibrillary acidic protein (GFAP) has been associated with astroglial injury. In an attempt to shed new light on factors potentially underlying past findings of structural brain alterations in AN, the current study investigated serum NF-L, tau protein, and GFAP levels longitudinally in AN patients undergoing weight restoration. Blood samples were obtained from 54 acutely underweight, predominantly adolescent female AN patients and 54 age-matched healthy control participants. AN patients were studied in the severely underweight state and again after short-term partial weight restoration. Group comparisons revealed higher levels of NF-L, tau protein, and GFAP in acutely underweight patients with AN compared to healthy control participants. Longitudinally, a decrease in NF-L and GFAP but not in tau protein levels was observed in AN patients upon short-term partial weight restoration. These results may be indicative of ongoing neuronal and astroglial injury during the underweight phase of AN. Normalization of NF-L and GFAP but not tau protein levels may indicate an only partial restoration of neuronal and astroglial integrity upon weight gain after initial AN-associated cell damage processes.

Hippocampal volume, function, and related molecular activity in anorexia nervosa: A scoping review

INTRODUCTION

Anorexia nervosa (AN) is a serious and persistent eating disorder, characterized by severe dietary restriction and weight loss, with a third of patients developing a  severe-enduring form. The factors contributing to this progression are poorly understood, although there is evidence for impairments in neural structures such as the hippocampus, an area particularly affected by malnutrition and chronic stress.

AREAS COVERED

This study aimed to map the evidence for alterations in hippocampal volume, function, and related molecular activity in anorexia nervosa. PubMed, PsycINFO, and Web of Science were searched for studies related to hippocampal function and integrity using a range of methodologies, such as neuropsychological paradigms, structural and functional magnetic resonance imaging, and analysis of blood components.

EXPERT OPINION

Thirty-nine studies were included in this review. The majority were neuroimaging studies, which found hippocampus-specific volumetric and functional impairments. Neuropsychological studies showed evidence for a specific memory and learning impairments. There was some evidence for molecular abnormalities (e.g. cortisol), although these were few studies. Taken together, our review suggests that the hippocampus might be a particular region of interest when considering neurobiological approaches to understanding AN. These findings warrant further investigation and may lead to novel treatment approaches.

Cognitive flexibility in acute anorexia nervosa and after recovery: A systematic review

Difficulties in cognitive flexibility-the ability to adapt effectively to changes in the environment and/or changing task demands-have been reported in anorexia nervosa (AN). However, findings are inconsistent across studies and it remains unclear which specific aspects of cognitive flexibility patients with AN may struggle with. This systematic review aimed to synthesise existing research on cognitive flexibility in AN and clarify differences between patients with acute AN, patients who are weight-restored and patients who are fully recovered from AN. Electronic databases were searched through to January 2020. 3,310 papers were screened and 70 papers were included in the final review. Although adults with acute AN performed worse in perceptual flexibility tasks and self-report measures compared to HCs, they did not exhibit deficits across all domains of cognitive flexibility. Adolescents with acute AN did not differ to HCs in performance on neurocognitive tasks despite self-reporting poorer cognitive flexibility. Overall, significant differences in cognitive flexibility between acute and recovered participants was not evident, though, the findings are limited by a modest number of studies. Recovered participants performed poorer than HCs in some neurocognitive measures, however, results were inconsistent across studies. These results have implications for the assessment of cognitive flexibility in AN and targeted treatment approaches.

Metacognition in individuals recovered from anorexia nervosa: a voxel-based morphometry study

Recent evidence shows that individuals with Anorexia Nervosa (AN) can be characterized by dysfunctional metacognition as well as reductions of gray matter volumes (GMV) in prefrontal brain regions involved in cognitive processes. However, whether these differences are reversible or stable markers has yet to be understood. Thus, we aimed at characterizing metacognition and brain morphometry in individuals recovered from AN (rec-AN). A combined psychometric-brain morphometry investigation on metacognitive functioning in rec-AN individuals was conducted. Fifteen healthy controls (HC) and fifteen rec-AN women underwent a psychometric assessment for metacognitive functioning and a high-resolution T1-weighted Magnetic Resonance Imaging measurement to assess global and regional brain volumes, using Voxel-Based Morphometry. The two groups did not differ for metacognitive functioning and GMV, while regional GMV reductions were observed in rec-AN compared to HC in the left Inferior Frontal Gyrus (IFG). While changes in metacognitive abilities may not represent a stable trait of AN, regional GMV reductions in brain regions devoted to specific cognitive functions, such as inhibitory/top-down control processes, can act as a neurobiological fingerprint for such condition. These findings can represent a promising hint for future investigations on the maintaining factors of AN.

Executive functioning and spatial processing in anorexia nervosa: an experimental study and its significance for the allocentric lock theory

PURPOSE

The allocentric lock theory (ALT) suggests that people with eating disorders have difficulties in multisensory integration in two reference frames-egocentric and allocentric, whereby the egocentric, but not allocentric, is impaired. This leads to a distorted body image that contributes to the development and maintenance of the disorder. The current study aimed to explore a facet of the ALT, namely, the visuo-spatial aspect, and its relation to cognitive flexibility in patients with anorexia nervosa (AN).

METHODS

Fifty-five participants took part in the study: 20 AN patients and 35 controls, matched by age and education. The object perspective taking test (OPTT) and the mental rotation test (MRT), tapping egocentric and allocentric representations, respectively, and a set-shifting task were administered. The brief symptom inventory was used to measure overall levels of distress.

RESULTS

AN patients showed higher level of distress. They performed poorer on the OPTT and set-shifting task but not on the MRT. The OPTT and MRT were correlated for controls but not for AN patients, while the set-shifting task and body mass index were associated with the OPTT but not with the MRT for the AN patients.

CONCLUSIONS

The findings support the ALT by demonstrating impaired visual egocentric representations and intact allocentric visual functions in AN patients, with cognitive flexibility associated only with the egocentric frame. Therefore, egocentric frame impairment in AN patients may be influenced by visual perception and cognitive flexibility deficiency.

LEVEL OF EVIDENCE

Level III: case-control analytic study.

Illness Perception in Adolescent Patients With Anorexia: Does It Play a Role in socio-Emotional and Academic Adjustment?

People’s beliefs about their illness have been shown to affect their adjustment. The aim of this study was to describe illness perception in adolescent patients with anorexia nervosa (AN) and assess its relationship with socio-emotional and academic adjustment following Leventhal’s Self-Regulation Model. Thirty-four female AN patients, with a mean age of 15.76 (SD = 2.00), completed the Revised Illness Perception Questionnaire (IPQ-R), the Psychosocial Adjustment to Illness Scale (PAIS) and the Hospital Anxiety and Depression Scale (HAD). Adolescent anorexia patients perceived that they had control over their illness and treatment would improve their condition. However, they also believed that it was highly distressing, going to last a long time and would have serious consequences. As for the causes of the disorder, they were attributed primarily to a specific eating disorder and psychological factors. The results showed that anorexia patients’ illness perceptions were related to socio-emotional and academic adjustment. In this sense, identity with the illness was associated with a worse academic adjustment, while emotional representation was associated with a worse emotional and social adjustment. These findings highlight how important it is for patients’ beliefs about their disease to be considered in the treatment of anorexia. In this respect, clinicians treating these patients should consider how certain beliefs affect their academic and socio-emotional adjustment. It would be interesting for patients to become aware of how these beliefs influence the strategies they use to cope with their disease as well as their adjustment to it.

Withdrawal from Extended, Intermittent Access to A Highly Palatable Diet Impairs Hippocampal Memory Function and Neurogenesis: Effects of Memantine

Background: Compulsive eating can be promoted by intermittent access to palatable food and is often accompanied by cognitive deficits and reduction in hippocampal plasticity. Here, we investigated the effects of intermittent access to palatable food on hippocampal function and neurogenesis. Methods: Male Wistar rats were either fed chow for 7 days/week (Chow/Chow group), or fed chow intermittently for 5 days/week followed by a palatable diet for 2 days/week (Chow/Palatable group). Hippocampal function and neurogenesis were assessed either during withdrawal or following renewed access to palatable food. Furthermore, the ability of the uncompetitive N-methyl-d-aspartate receptor (NMDAR) antagonist memantine to prevent the diet-induced memory deficits and block the maladaptive feeding was tested. Results: Palatable food withdrawn Chow/Palatable rats showed both a weakened ability for contextual spatial processing and a bias in their preference for a “novel cue” over a “novel place,” compared to controls. They also showed reduced expression of immature neurons in the dentate gyrus of the hippocampus as well as a withdrawal-dependent decrease of proliferating cells. Memantine treatment was able both to reverse the memory deficits and to reduce the excessive intake of palatable diet and the withdrawal-induced hypophagia in food cycling rats. Conclusions: In summary, our results provide evidence that withdrawal from highly palatable food produces NMDAR-dependent deficits in hippocampal function and a reduction in hippocampal neurogenesis.

Systematic Review: Overlap Between Eating, Autism Spectrum, and Attention-Deficit/Hyperactivity Disorder

Background: Links between eating disorders (EDs) [e.g., anorexia nervosa (AN), bulimia nervosa (BN), and binge eating disorder (BED)] and the major neurodevelopmental disorders of autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD) have been repeatedly highlighted. In both ASD and ADHD, these links range from an elevated risk for EDs to common symptomatic overlaps and etiological commonalities with EDs. Methods: We performed a systematic literature search (through July 2019) with Medline via Ovid for epidemiological data on EDs (AN, BN, and BED) in combination with both ASD and ADHD. Results: The reviewed studies showed that, on average, 4.7% of patients with certain ED diagnoses (AN, BN, or BED) received an ASD diagnosis. Reliable data on the prevalence of EDs in ASD samples are still scarce. Comorbid ASD is most commonly diagnosed in patients with AN. The prevalence of ADHD in EDs ranged between 1.6% and 18%. Comorbid ADHD was more often reported in the AN-binge eating/purging subtype and BN than in the AN restrictive subtype. The prevalence of EDs in ADHD ranged between no association and a lifetime prevalence of 21.8% of developing an ED in women with ADHD. Conclusions: Studies on the prevalence rates of EDs in ADHD and ASD and vice versa are heterogeneous, but they indicate frequent association. While there is growing evidence of clinical overlaps between the three disorders, it remains difficult to determine whether overlapping characteristics (e.g., social withdrawal) are due to common comorbidities (e.g., depression) or are instead primarily associated with EDs and neurodevelopmental disorders. Furthermore, prospective studies are required to better understand how these disorders are related and whether ADHD and ASD could be either specific or nonspecific predisposing factors for the development of EDs.

Clinical and personality characteristics of adolescents with anorexia nervosa with or without non-suicidal self-injurious behavior

PURPOSE

About one-fifth of patients with anorexia nervosa (AN) engage in non-suicidal self-injury (NSSI). This study examined clinical and temperament profile of female adolescents with both disorders (AN+NSSI) as compared with peers with AN only.

METHODS

A consecutive sample of 73 female adolescents with AN (mean age: 13.77 years), who had been admitted to inpatient or day-hospital services, received clinical, cognitive, and temperament/character evaluations. Of them, 32 met DSM-5 criteria also for NSSI. Assessments included demographics, standard nutrition parameters, Youth Self-Report (YSR), Wechsler Intelligence Scale for Children IV (WISC-IV), Temperament and Character Inventory (TCI), and Global Assessment of Functioning (GAF).

RESULTS

No differences were detected between AN+NSSI and AN in demographics, body mass index, or age at onset of AN. AN+NSSI had higher rate of binging and purging, higher YSR scores for both internalizing and externalizing psychopathology, lower total IQ, and lower Self-directedness and Cooperativeness scores.

CONCLUSIONS

These data suggest that adolescents with AN+NSSI have psychopathological, cognitive and overall character features that differ from patients with AN only. These characteristics may have implications for treatment and outcome.

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.

Medical Complications of Anorexia Nervosa and Bulimia Nervosa

Anorexia nervosa and bulimia nervosa are mental illnesses with associated complications affecting all body systems with arguably the highest mortality of all mental health disorders. A comprehensive medical evaluation is an essential first step in the treatment of anorexia nervosa and bulimia nervosa. Weight restoration and cessation of purging behaviors are often essential components in the management of medical complications of these illnesses.

General and Eating Disorder Specific Flexibility: Development and Validation of the Eating Disorder Flexibility Index (EDFLIX) Questionnaire

Findings from studies investigating cognitive flexibility in eating disorders (EDs) are inconsistent, and although neuropsychological tests are commonly used to measure these skills, they may not be particularly effective in predicting everyday functioning. Also, extant studies have largely focused on flexibility in anorexia nervosa (AN), with assessments targeting general rather than specific flexibility, and cognitive, rather than behavioral flexibility. Knowledge regarding ED specific flexibility and flexibility in bulimia nervosa (BN) and binge eating disorder (BED) is still scarce. The aim of this study was to develop and validate a novel measure assessing general and ED specific flexibility in a diagnostically diverse sample, and in healthy controls (HCs). A sample of 207 adult individuals with EDs (55% AN, 29% BN, 16% BED) and 288 HCs responded to an online, 51-item, pilot questionnaire on ED specific and general flexibility. In addition, participants completed the shift subscale from the Behavior Rating Inventory of Executive Function Adult version (BRIEF-A), and the Eating Disorder Diagnostic Scale (EDDS). A principal component analysis (PCA) in the clinical sample yielded a 36-item, three-factor solution capturing general flexibility, flexibility related to food and exercise, and flexibility concerning body shape and weight. Results showed that the measure had good to excellent internal consistency, and good convergent validity. A confirmatory factor analysis (CFA) using data from HCs revealed good fit indexes, supporting the original factor solution. A receiver operating characteristics analysis (ROC) demonstrated excellent accuracy in distinguishing scores from those with and without EDs. A cutoff score of 136 yielded the most balanced sensitivity and specificity. Significant differences in general and ED specific flexibility were found between individuals with and without EDs. Overall, HCs achieved the highest flexibility scores, followed by those with BED, BN, and AN. In sum this novel measure, the Eating Disorder Flexibility Index (EDFLIX) questionnaire, was found to be reliable and valid in the assessment of cognitive and behavioral flexibility, with results offering support for the conceptual distinction between general and ED related flexibility. The study also provides strong evidence for the discriminant validity of the EDFLIX with results revealing significant differences in flexibility in people with and without EDs. In addition, significant differences in flexibility also emerged when comparing diagnostic groups, indicating the utility of the assessment instrument for classification purposes.

Cognitive remediation therapy in Mexico as a treatment for Anorexia Nervosa: A case study

The purpose of this study was to conduct a preliminary evaluation of cognitive remediation therapy (CRT) as part of the treatment of a patient with anorexia nervosa (AN) from Mexico. The participant was a 21-year-old woman with a body mass index (BMI) of 14.7, who had suffered from the disorder for 10 years. Using a pre-post treatment design, changes were evaluated using four neuropsychological tests, two tests to measure the AN symptoms and two to measure psychological distress (depression and anxiety). BMI was also evaluated before and after the intervention. The results of the present study were similar to those reported for patients from English-speaking countries. The average percentage of favorable change in the different measures was higher than 30%, except for BMI, which increased by only 21%. The results suggest that the inclusion of CRT in AN treatment programs in Mexico is a potentially viable option.

The improvement in neurocognitive functioning in anorexia nervosa adolescents throughout the integrative model of psychotherapy including cognitive remediation therapy

BACKGROUND

Patients with anorexia nervosa (AN) experience difficulties in neurocognitive functioning in the acute phase of illness which might be related to clinical presentation, but also in the apparently remitted state after weight recovery. Among the most commonly reported persistent deficits is cognitive inflexibility, which can be interpreted as a vulnerability trait or a "neuropsychological scar" reflecting the detrimental effect of prolonged semi-starvation in patients with a long duration of illness. Studies of adolescent samples with a relatively short clinical course may enable avoiding the effect of prolonged illness and help to determine whether neuropsychological deficits are trait or state dependent. The aim of this study is to assess cognitive functioning in adolescents with AN before and after the inpatient treatment programme, including cognitive remediation therapy (CRT).

METHODS

Forty-seven adolescent female inpatients with AN diagnosed according to DSM-5 and fifty healthy female adolescents matched for the education level and age were recruited. The patients underwent a multimodal treatment including a ten-week CRT. The standardized and cross-validated neuropsychological (Trail Making Test - TMT A and B, Color-Word Stroop Task - CWST, Ruff Figural Fluency Test - RFFT) and clinical measurements (Beck Depression Inventory - BDI, Eating Attitude Test - EAT-26, Yale-Brown Obsessive Compulsive Scale - Y-BOCS) were used to assess both clinical (in the acute phase and after partial weight recovery) and control subjects.

RESULTS

Initially, AN patients performed significantly worse compared to the controls, but afterwards, inpatient treatment improvement was noted on all examined measures. In a few subtests (TMT, CWST) performance of AN patients after the programme was still significantly poorer than in HC.

CONCLUSIONS

Cognitive inflexibility in adolescent AN patients, as measured with TMT, CWST, and RFFT tends to improve after therapy. Nevertheless, a few neuropsychological subtests which did not show complete normalization may warrant attention in subsequent studies. Further research including control intervention is needed to conclude whether CRT intervention affects the outcome.

Cognitive impairment in eating disorder patients of short and long-term duration: a case-control study

Introduction: Several studies have noted the potentially negative effect of eating disorders (ED) on cognitive performance. Objective: To compare the impact of the duration of abnormal eating behaviors on cognitive performance in a sample of people with short- and long-term eating disorders and in two control groups matched for age. Method: The neuropsychological performance of 82 women diagnosed with an eating disorder were compared with two control groups from the community of 66 healthy women. Time of duration of the disorder was less than two years in half of the clinical sample, and more than 10 years in the other half. The following instruments were used to measure neuropsychological performance: the Matrix Test, the Stroop task, the Trail-Making Test, the Tower of London Test, the Posner Spatial Task, the Rey's Complex Figure, the Wechsler Vocabulary Test, and the Hayling Completion Test. Results: It showed that persons with long-term ED presented more impaired neuropsychological profiles, but not in all areas. In contrast, the short-term ED group presented similar profiles to the control groups. Discussion: This study highlights the positive association between cognitive impairment and time of evolution of ED, above all in perceptual measures and non-verbal memory. Considering the effect of the evolution of ED cognitive performance (especially in long-term patients) may further our understanding of the development of the disorder and the factors that may favor its persistence.

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.

Temporal Processing of Joyful and Disgusting Food Pictures by Women With an Eating Disorder

The present study used the presentation of food pictures and judgements about their duration to assess the emotions elicited by food in women suffering from an eating disorder (ED). Twenty-three women diagnosed with an ED, namely anorexia (AN) or bulimia nervosa (BN), and 23 healthy controls (HC) completed a temporal bisection task and a duration discrimination task. Intervals were marked with emotionally pre-rated pictures of joyful and disgusting food, and pictures of neutral objects. The results showed that, in the bisection task, AN women overestimated the duration of food pictures in comparison to neutral ones. Also, compared to participants with BN, they perceived the duration of joyful food pictures as longer, and tended to overestimate the duration of the disgusting ones. These effects on perceived duration suggest that AN women experienced an intense reaction of fear when they were confronted to food pictures. More precisely, by having elevated the arousal level and activated the defensive system, food pictures seemed to have speeded up the rhythm of the AN participants’ internal clock, which led to an overestimation of images’ duration. In addition, the results revealed that, in both tasks, ED women presented a lower temporal sensitivity than HC, which was related to their ED symptomatology (i.e., BMI, restraint and concern) and, particularly, to their weaker cognitive abilities in terms of attention, processing speed and working memory. Considered all together, the findings of the present experiment highlight the role of fear and anxiety in the manifestations of AN and point out the importance of considering non-temporal factors in the interpretation of time perception performance.

Impaired central coherence in patients with anorexia nervosa

The purpose of this study was to investigate the characteristics of central coherence in patients with anorexia nervosa (AN). 22 female patients with AN (median age = 31.50 (QD = 8.13) years) and 33 female healthy controls (HC) (median age = 28.00 (QD = 8.50) years) participated in the study. Their central coherence was assessed with the Rey Complex Figure Task (RCFT). Clinical symptoms were evaluated with the Beck Depression Inventory-II and the State-Trait Anxiety Inventory-Form JYZ. The results showed that AN patients' Central Coherence Index and accuracy scores in copy, 3-min delayed recall and 30-min delayed recall tasks of the RCFT were significantly lower than those of HC. Moreover, the significant differences in Central Coherence Index score in copy task and accuracy scores in 3-min delayed recall and 30-min delayed recall tasks remained when the effects of depression, anxiety and starvation were eliminated statistically. These findings may explain some characteristics of AN patients such as focusing on local rather than global picture in their perception of body or life.

An ecological approach to the behavioral assessment of executive functions in anorexia nervosa

The use of ecological tests to assess executive functions (EFs) in patients with anorexia nervosa (AN) has not examined extensively. The objective of this study was to analyze and compare the performance of patients with AN and healthy controls (HCs) on standard versus ecologically valid tests on EFs. Sixty-two females aged between 16 and 42 who were diagnosed with AN and 70 matched HCs completed 2 neuropsychological test batteries: standard tests (WCST, TMT, Stroop, ToL, fluency test) and the Behavioral Assessment of Dysexecutive Syndrome (BADS). On the standard tests, patients with AN produced more perseverative response and were slower than HCs in the TMT; in contrast, they scored as well as HCs on tasks that assessed categorization, interference in color naming, planning and semantic fluency. Conversely, there were differences in the ecological tests with patients with AN systematically slower in the resolution of complex tasks. Results demonstrated the power of ecological tests in capturing selective impairments in multifaceted and unstructured tests. Patients with AN experienced systematic deceleration in the resolution of ecological tasks. Also, the increased time needed to solve the tasks, was not reflected in overall improvement in performance. This evidence is further discussed with respect to central coherence.

Inattentive Attention-Deficit/Hyperactivity Disorder, Stimulant Medication, and Weight Loss in a 15-Year-Old Girl: Are We Enabling the Development of an Eating Disorder?

Nicole is a 15-year-old girl presenting to the Developmental Behavioral Pediatrics Clinic with symptoms of the inattentive type of Attention-Deficit/Hyperactivity Disorder (ADHD) and declining school performance over the last year. She expressed frustration over her inability to concentrate on schoolwork. Assuming that her poor grades were secondary to lack of effort, her parents withdrew privileges. Nicole became increasingly depressed. She stopped participating in activities, she previously enjoyed, and her parents reported that she stopped singing in the shower. After talking to a cousin with ADHD, Nicole concluded that she had ADHD as well. She asked her parents to arrange for an evaluation.Nicole met DSM-5 criteria for the diagnosis of inattentive ADHD and was started on a stimulant medication (mixed amphetamine salts). She had symptoms of a coexisting depression, although she did not meet criteria for diagnosis of a depressive disorder. At a 3-week follow-up visit, she showed improvement in targeted ADHD symptoms; homework was now easier and her grades improved. At a 2-month follow-up, Nicole's weight dropped from 53 kg (47th percentile) prestimulant treatment to 49 kg (31st percentile). She reported appetite suppression after taking the stimulant but did not feel that her eating habits had changed significantly. Her father reported that she had a preference for junk food and snacks. Nicole did not enjoy exercising and did not participate in extracurricular sports.She weighed herself several times a day, as she was worried about losing too much weight. Nicole's mood continued to be low, despite the fact that her grades improved, and her parents were more understanding of her challenges. She was otherwise healthy and reported regular menstrual cycles. Nicole requested an increase in the dose of stimulant medication for greater improvement in concentration during homework and in school.Her pediatric clinician was concerned about the possibility of an eating disorder in addition to depression. She asked herself, "Are we treating inattentive ADHD effectively or are we enabling an eating disorder?"

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.

The Role of Working Memory for Cognitive Control in Anorexia Nervosa versus Substance Use Disorder

Prefrontal cortex executive functions, such as working memory (WM) interact with limbic processes to foster impulse control. Such an interaction is referred to in a growing body of publications by terms such as cognitive control, cognitive inhibition, affect regulation, self-regulation, top-down control, and cognitive–emotion interaction. The rising trend of research into cognitive control of impulsivity, using various related terms reflects the importance of research into impulse control, as failure to employ cognitions optimally may eventually result in mental disorder. Against this background, we take a novel approach using an impulse control spectrum model – where anorexia nervosa (AN) and substance use disorder (SUD) are at opposite extremes – to examine the role of WM for cognitive control. With this aim, we first summarize WM processes in the healthy brain in order to frame a systematic review of the neuropsychological, neural and genetic findings of AN and SUD. In our systematic review of WM/cognitive control, we found n = 15 studies of AN with a total of n = 582 AN and n = 365 HC participants; and n = 93 studies of SUD with n = 9106 SUD and n = 3028 HC participants. In particular, we consider how WM load/capacity may support the neural process of excessive epistemic foraging (cognitive sampling of the environment to test predictions about the world) in AN that reduces distraction from salient stimuli. We also consider the link between WM and cognitive control in people with SUD who are prone to ‘jumping to conclusions’ and reduced epistemic foraging. Finally, in light of our review, we consider WM training as a novel research tool and an adjunct to enhance treatment that improves cognitive control of impulsivity.

Is overestimation of body size associated with neuropsychological weaknesses in anorexia nervosa?

BACKGROUND

Recent research indicates some evidence of neuropsychological weaknesses in visuospatial memory, central coherence and set-shifting in adults with anorexia nervosa (AN). The growing interest in neuropsychological functioning of patients with AN is based upon the assumption that neuropsychological weaknesses contribute to the clinical features of the illness. However, due to a paucity of research on the connection between neuropsychological difficulties and the clinical features of AN, this link remains hypothetical. The main objective of this study was to explore the association between specific areas of neuropsychological functioning and body size estimation in patients with AN and healthy controls.

METHODS

The sample consisted of 36 women diagnosed with AN and 34 healthy female controls. Participants were administered the continuous visual memory test and the recall trials of Rey Complex Figure Test to assess visual memory. Central coherence was assessed using the copy trial of Rey Complex Figure Test, and the Wisconsin Card Sorting Test was used to assess set-shifting. Body size estimation was assessed with a computerized morphing programme.

RESULTS

The analyses showed no significant correlations between any of the neuropsychological measures and body size estimation.

CONCLUSION

The results suggest that there is no association between these areas of neuropsychological difficulties and body size estimation among patients with AN. Copyright © 2017 John Wiley & Sons, Ltd and Eating Disorders Association.

Neurocognitive Treatments for Eating Disorders and Obesity

PURPOSE OF REVIEW

Recent research has highlighted executive function and neurocognitive deficits among individuals with eating and weight disorders, identifying a potential target for treatment. Treatments targeting executive function for eating and weight disorders are emerging. This review aims to summarize the recent literature evaluating neurocognitive/executive function-oriented treatments for eating and weight disorders and highlights additional work needed in this area.

RECENT FINDINGS

Cognitive remediation therapy (CRT) for anorexia nervosa has been the most extensively studied neurocognitive treatment for eating disorders. Results demonstrate that CRT improves executive function and may aid in the reduction of eating disorder symptomatology. Computer training programs targeting modifying attention and increasing inhibition are targeting reduction of binge eating and weight loss with modest success. Neurocognitive treatments are emerging and show initial promise for eating and weight disorders. Further research is necessary to determine whether these treatments can be used as stand-alone treatments or whether they need to be used as an adjunct to or in conjunction with other evidence-based treatments to improve outcomes.

Control over interfering memories in eating disorders

INTRODUCTION

Recent studies have suggested that patients suffering from either anorexia nervosa (AN) or bulimia nervosa (BN) exhibit abnormal performance in the ability to control cognitive interference in response selection.

METHOD

We assessed the status of cognitive control in episodic memory by addressing the ability to inhibit interfering memories. To this end, we used the retrieval-practice paradigm, which allows for measuring both the beneficial and the detrimental effects of memory practice. The latter phenomenon, known as retrieval-induced forgetting (RIF), is thought to reflect an adaptive inhibitory mechanism aimed at reducing competition in memory retrieval. Twenty-seven healthy controls and 27 patients suffering from eating disorders (either AN or BN) performed a retrieval-practice paradigm and a control task addressing general reactivity and filled a self-report questionnaire on impulsivity.

RESULTS

No differences between patients and healthy controls were observed for the beneficial effects of practice. The same pattern also emerged for RIF. However, when patients with AN and BN were analyzed separately, a clear dissociation emerged: patients with AN displayed no hint of RIF, whereas patients with BN showed an intact memory suppression performance. No group differences emerged in the control task.

CONCLUSIONS

Our findings suggest a specific impairment in the ability to suppress interfering memories in patients with AN, thus extending current evidence of cognitive control deficits in AN to episodic memory.

Neuropsychological function in individuals with morbid obesity: a cross-sectional study

BACKGROUND

Previous research has shown cognitive dysfunction to be present in a significant number of individuals with obesity. The objective of this study was to assess the neuropsychological profile of morbidly obese patients referred to weight-loss treatment.

METHODS

An extensive battery of neuropsychological tests with well-known normative data covering various cognitive domains was administered to 96 patients. The test results were transformed to z-scores for comparisons with normative data. As a means of determining level of cognitive impairment within the group, deficit scores were applied. Group comparisons on the different cognitive domains were conducted between patients with depressive symptoms and patients reporting no such symptoms.

RESULTS

As illustrated in mean z-scores, the patients demonstrated lower performance compared to normative data on visual memory (mean -.26, CI -.43 to -.09, p = .003), speed of information processing (mean -.22, CI -.34 to -.09, p = .001), executive functions (mean -.28, CI -.40 to -.16, p < .001), and attention/vigilance (mean -.25, CI -.37 to -.13, p < .001). Their performance was good on verbal fluency (mean .24, CI .04 to .44, p = .016) and verbal memory (mean .55, CI .38 to .72, p < .001). No significant performance differences were observed in the cognitive domains of visuospatial ability, motor function, and working memory. The deficit scores, however, revealed working memory and motor function to be significantly impaired within the group as well. Patients with depressive symptoms differed from patients without such symptoms on visual memory (mean .43, CI .07 to .80, p = .021).

CONCLUSIONS

Some characteristic cognitive weaknesses and strengths were evident at the group level, although pronounced variation was observed. Deficits in executive functions, information processing, and attention should be taken into consideration in clinical practice.

Neurocognitive functions and social functioning in young females with recent-onset anorexia nervosa and recovered individuals

BACKGROUND

Young individuals with anorexia nervosa (AN) or recovered from AN display impairments of social function. To date, however, it is not clear whether they differ from controls with respect to neurocognitive performance and whether those functions contribute to the compromised social function observed in individuals with AN.

METHODS

We included 43 young females with first-episode AN, 28 individuals recovered from adolescent-onset AN, and 41 control individuals (14-22 yr), all without comorbid autism spectrum disorder. We compared the performance of participants across groups in seven neurocognitive functions relevant to social functioning: set-shifting, local processing, processing speed, working memory, sustained attention, verbal memory, and verbal abstraction. Further, we tested the association between neurocognitive function and social function, measured by Autism Diagnostic Observation Schedule (ADOS), with an ordinal logistic regression model.

RESULTS

First, participants did not differ on any neurocognitive function across groups. Second, only the neurocognitive function "verbal memory" was significantly associated with social function. Higher performance in verbal memory was associated with lower odds of impaired social function. Diagnostic group remained a significant factor, but the absence of an interaction between group and neurocognitive performance indicated that the association between verbal memory and social function was independent of group membership.

CONCLUSION

Young individuals with AN and those recovered from AN did not differ from controls with respect to neurocognitive performance. Verbal memory was associated with social function in all groups.

Reward-Based Spatial Learning in Teens With Bulimia Nervosa

OBJECTIVE

To assess the functioning of mesolimbic and fronto-striatal areas involved in reward-based spatial learning in teenaged girls with bulimia nervosa (BN) that might be involved in the development and maintenance of maladaptive behaviors characteristic of the disorder.

METHOD

We compared functional magnetic resonance imaging blood oxygen level-dependent response in 27 adolescent girls with BN to that of 27 healthy, age-matched control participants during a reward-based learning task that required learning to use extra-maze cues to navigate a virtual 8-arm radial maze to find hidden rewards. We compared groups in their patterns of brain activation associated with reward-based spatial learning versus a control condition in which rewards were unexpected because they were allotted pseudo-randomly to experimentally prevent learning.

RESULTS

Both groups learned to navigate the maze to find hidden rewards, but group differences in brain activity associated with maze navigation and reward processing were detected in the fronto-striatal regions and right anterior hippocampus. Unlike healthy adolescents, those with BN did not engage the right inferior frontal gyrus during maze navigation, activated the right anterior hippocampus during the receipt of unexpected rewards (control condition), and deactivated the left superior frontal gyrus and right anterior hippocampus during expected reward receipt (learning condition). These patterns of hippocampal activation in the control condition were significantly associated with the frequency of binge-eating episodes.

CONCLUSION

Adolescents with BN displayed abnormal functioning of the anterior hippocampus and fronto-striatal regions during reward-based spatial learning. These findings suggest that an imbalance in control and reward circuits may arise early in the course of BN. Clinical trial registration information-An fMRI Study of Self-Regulation in Adolescents With Bulimia Nervosa; https://clinicaltrials.gov/; NCT00345943.

Attention Network Dysfunction in Bulimia Nervosa - An fMRI Study

OBJECTIVE

Recent evidence has suggested an increased rate of comorbid ADHD and subclinical attentional impairments in bulimia nervosa (BN) patients. However, little is known regarding the underlying neural mechanisms of attentional functions in BN.

METHOD

Twenty BN patients and twenty age- and weight-matched healthy controls (HC) were investigated using a modified version of the Attention Network Task (ANT) in an fMRI study. This design enabled an investigation of the neural mechanisms associated with the three attention networks involved in alerting, reorienting and executive attention.

RESULTS

The BN patients showed hyperactivation in parieto-occipital regions and reduced deactivation of default-mode-network (DMN) areas during alerting compared with HCs. Posterior cingulate activation during alerting correlated with the severity of eating-disorder symptoms within the patient group. Conversely, BN patients showed hypoactivation during reorienting and executive attention in anterior cingulate regions, the temporo-parietal junction (TPJ) and parahippocampus compared with HCs, which was negatively associated with global ADHD symptoms and impulsivity, respectively.

DISCUSSION

Our findings demonstrate altered brain mechanisms in BN associated with all three attentional networks. Failure to deactivate the DMN and increased parieto-occipital activation required for alerting might be associated with a constant preoccupation with food or body image-related thoughts. Hypoactivation of executive control networks and TPJ might increase the likelihood of inattentive and impulsive behaviors and poor emotion regulation. Thus, dysfunction in the attentional network in BN goes beyond an altered executive attentional domain and needs to be considered in the diagnosis and treatment of BN.

Literature Review of Cognitive Neuroscience and Anorexia Nervosa

Studies published between the beginning of 2013 and May 2015 on the neuropsychological functioning of patients with anorexia nervosa compared with healthy participants framed in the context of the Research Domain Criteria matrix identifies evidence for functional differences in three domains: Negative Valance Systems-negative attentional biases and lack of neural responsivity to hunger; Cognitive Systems-limited congruence between clinical and cognitive performance, poorer non-verbal than verbal performance, altered attentional styles to disorder related stimuli, perceptual processing impairment in discriminating body images, weaknesses in central coherence, set shifting weaknesses at low weight status, decision-making weaknesses, and greater neural resources required for working memory; Systems for Social Processes-patients appear to have a different attentional response to faces, and perception and understanding of self and others. Hence, there is evidence to suggest that patients with anorexia nervosa have a specific neuropsychological performance style across tasks in three domains of functioning. Some current controversies and areas for future development are identified.

A debate on working memory and cognitive control: can we learn about the treatment of substance use disorders from the neural correlates of anorexia nervosa?

BACKGROUND

Anorexia Nervosa (AN) is a debilitating, sometimes fatal eating disorder (ED) whereby restraint of appetite and emotion is concomitant with an inflexible, attention-to-detail perfectionist cognitive style and obsessive-compulsive behaviour. Intriguingly, people with AN are less likely to engage in substance use, whereas those who suffer from an ED with a bingeing component are more vulnerable to substance use disorder (SUD).

DISCUSSION

This insight into a beneficial consequence of appetite control in those with AN, which is shrouded by the many other unhealthy, excessive and deficit symptoms, may provide some clues as to how the brain could be trained to exert better, sustained control over appetitive and impulsive processes. Structural and functional brain imaging studies implicate the executive control network (ECN) and the salience network (SN) in the neuropathology of AN and SUD. Additionally, excessive employment of working memory (WM), alongside more prominent cognitive deficits may be utilised to cope with the experience of negative emotions and may account for aberrant brain function. WM enables mental rehearsal of cognitive strategies while regulating, restricting or avoiding neural responses associated with the SN. Therefore, high versus low WM capacity may be one of the factors that unites common cognitive and behavioural symptoms in those suffering from AN and SUD respectively. Furthermore, emerging evidence suggests that by evoking neural plasticity in the ECN and SN with WM training, improvements in neurocognitive function and cognitive control can be achieved. Thus, considering the neurocognitive processes of excessive appetite control and how it links to WM in AN may aid the application of adjunctive treatment for SUD.

Altered SPECT (123)I-iomazenil Binding in the Cingulate Cortex of Children with Anorexia Nervosa

Several lines of evidence suggest that anxiety plays a key role in the development and maintenance of anorexia nervosa (AN) in children. The purpose of this study was to examine cortical GABA(A)-benzodiazepine receptor binding before and after treatment in children beginning intensive AN treatment. Brain single-photon emission computed tomography (SPECT) measurements using (123)I-iomazenil, which binds to GABA(A)-benzodiazepine receptors, was performed in 26 participants with AN who were enrolled in a multimodal treatment program. Sixteen of the 26 participants underwent a repeat SPECT scan immediately before discharge at conclusion of the intensive treatment program. Eating behavior and mood disturbances were assessed using Eating Attitudes Test with 26 items (EAT-26) and the short form of the Profile of Mood States (POMS). Clinical outcome scores were evaluated after a 1-year period. We examined association between relative iomazenil-binding activity in cortical regions of interest and psychometric profiles and determined which psychometric profiles show interaction effects with brain regions. Further, we determined if binding activity could predict clinical outcome and treatment changes. Higher EAT-26 scores were significantly associated with lower iomazenil-binding activity in the anterior and posterior cingulate cortex. Higher POMS subscale scores were significantly associated with lower iomazenil-binding activity in the left frontal, parietal cortex, and posterior cingulate cortex (PCC). "Depression-Dejection" and "Confusion" POMS subscale scores, and total POMS score showed interaction effects with brain regions in iomazenil-binding activity. Decreased binding in the anterior cingulate cortex and left parietal cortex was associated with poor clinical outcomes. Relative binding increases throughout the PCC and occipital gyrus were observed after weight gain in children with AN. These findings suggest that cortical GABAergic receptor binding is altered in children with AN. This may be a state-related change, which could be used to monitor and guide the treatment of eating disorders.

Increased frontal electroencephalogram theta amplitude in patients with anorexia nervosa compared to healthy controls

OBJECTIVE

To conduct a blind study of quantitative electroencephalogram-band amplitudes in patients with anorexia nervosa (AN) and healthy controls.

METHODS

Twenty-one patients with AN and 24 controls were examined with eyes-closed 16-channel electroencephalogram. Main variables were absolute alpha, theta, and delta amplitudes in frontal, temporal, and posterior regions.

RESULTS

There were no significant differences between the AN patients and controls regarding absolute regional band amplitudes in μV. Borderline significance was found for anterior theta (P=0.051). Significantly increased left and right frontal electrode theta amplitude was found in AN patients (F3, P=0.014; F4, P=0.038) compared to controls. Significant differences were also observed for secondary variables: lower values for relative parietooccipital delta and frontocentral alpha activity among AN patients than among controls.

CONCLUSION

We observed slight excess frontal theta and lower relative alpha and delta amplitudes among AN patients than among controls. This pattern is possibly related to a slight frontal lobe dysfunction in AN, or it may reflect increased attention/vigilance or another state-related change in patients with AN compared to healthy controls.