Neurocognitive functioning in bulimia nervosa: the role of neuroendocrine, personality and clinical aspects

Testing associations between assessments of cognitive flexibility and eating disorder symptoms in adolescent bulimia nervosa

OBJECTIVE

Cognitive rigidity, or difficulty adapting to changing demands, is commonly observed in anorexia nervosa. Less is known, however, about cognitive flexibility (CF) in bulimia nervosa (BN) and, particularly, adolescence. Clarifying this relation and best assessment practices may guide informed clinical decision-making. The current study compared how two measures of CF (i.e., Wisconsin Card Sort Task [WCST] and Trail Making Task [TMT]) relate to BN symptoms among adolescents.

METHODS

Data from a subsample (n = 78) of adolescents with BN were analyzed. Linear and hurdle regressions were used to compare the effects of WCST perseverative errors and TMT performance on Eating Disorder Examination Global Scores, objective binge episodes, and self-induced vomiting episodes (SVEs) at baseline and end-of-treatment (EOT).

RESULTS

Neither CF measure associated with baseline BN symptoms. TMT performance positively associated with the likelihood of engaging in SVEs at EOT (𝛽 = 0.47, p = 0.01, 95% confidence interval [CI] = [0.11-0.84]) and, among adolescents who endorsed ≥1 SVE at EOT, WCST perseverative errors (𝛽 = 0.05, p = 0.005, 95% CI = [0.01-0.08]) positively associated with SVE frequency at EOT.

DISCUSSION

The overall lack of associations between CF and outcomes suggests that cognitive rigidity may not be as relevant to the clinical profile of adolescent BN as for anorexia nervosa. In the few significant associations that emerged, the WCST and TMT uniquely predicted the severity of vomiting at EOT in this sample. Given the lack of CF deficits, future work should aim to test the role of other executive functions (e.g., impulsivity), in addition to CF, to determine which deficits are present in adolescent BN and may predict outcomes.

PUBLIC SIGNIFICANCE

Patients with eating disorders often have difficulties thinking flexibly, which may interfere with their recovery. We tested two ways of measuring flexible thinking in adolescents with BN. Overall, flexible thinking was not associated with symptom-level outcomes. However, less flexible thinking at the start of treatment predicted self-induced vomiting at EOT. If findings are replicable, then assessing and addressing flexible thinking could improve outcomes for adolescents with BN.

Intact general and food-specific task-switching abilities in bulimia-spectrum eating disorders

OBJECTIVE

Prior work evaluating cognitive flexibility (i.e., the ability to alter behavior in response to environmental changes) in bulimia-spectrum eating disorders (BN-ED) has produced mixed findings, perhaps due to reliance on set-shifting paradigms that do not effectively isolate cognitive flexibility. Task-switching paradigms are more precise, but no study has examined task-switching in BN-ED. Further, no study has examined whether cognitive flexibility deficits in BN-ED are disorder-specific (e.g., confined to food-related responses). Thus, the present study re-evaluated cognitive flexibility in BN-ED using general and food-specific task-switching paradigms.

METHOD

Individuals with BN-ED (n = 28) and healthy controls (HC; n = 39) completed a cued color-shape switching task (CCSST) and a novel food-specific variation (FCCSST). We compared BN-ED and HC on switch costs (reflective of transient task-switching) and mix costs (reflective of maintenance of switching behavior).

RESULTS

Switch and mix costs were not significantly different between BN-ED and HC in terms of either accuracy or reaction time on the CCSST or FCCSST.

CONCLUSIONS

Findings suggest neither general nor food-specific cognitive flexibility is impaired in BN-ED. Rigidity in BN-ED (e.g., continued engagement in compensatory behaviors despite psychoeducation that these behaviors are ineffective for weight loss) may be a result of other neurocognitive impairments rather than cognitive flexibility deficits.

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.

Central coherence and set-shifting between nonunderweight eating disorders and anorexia nervosa: A systematic review and meta-analysis

OBJECTIVE

This systematic review and meta-analysis compared previously documented inefficiencies in central coherence and set-shifting between people with nonunderweight eating disorders (bulimia nervosa and binge-eating disorder) and people with anorexia nervosa.

METHOD

We performed random-effects meta-analyses on 16 studies (1,112 participants) for central coherence and 38 studies (3,505 participants) for set-shifting. Random effects meta-regressions were used to test whether the effect sizes for people with nonunderweight eating disorders were significantly different from the effect sizes for people with anorexia nervosa.

RESULTS

People with anorexia nervosa (Hedge's g = -0.53, 95% CIs: -0.80, -0.27, p < .001) and bulimia nervosa (Hedge's g = -0.70, 95% CIs: -1.14, -0.25, p = .002), but not binge-eating disorder, had significantly poorer central coherence than healthy controls. Similarly, people with anorexia nervosa (Hedge's g = -0.38, 95% CIs: -0.50, -0.26, p < .001) and bulimia nervosa (Hedge's g = -0.55, 95% CIs: -0.81, -0.29, p < .001), but not binge-eating disorder, had significantly poorer set-shifting than healthy controls. The effect sizes for people with nonunderweight eating disorders did not significantly differ from those for people with anorexia nervosa.

DISCUSSION

Our meta-analysis was underpowered to make definitive judgments about people with binge-eating disorder. However, we found that people with bulimia nervosa clearly have central coherence and set-shifting inefficiencies which do not significantly differ from those observed in people with anorexia nervosa. Clinically, this suggests that people with bulimia nervosa might benefit from adjunctive approaches to address these inefficiencies, such as cognitive remediation therapy.

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

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

Personality Traits as Markers of Psychosis Risk in Kenya: Assessment of Temperament and Character

Specific personality traits have been proposed as a schizophrenia-related endophenotype and confirmed in siblings at risk for psychosis. The relationship of temperament and character with psychosis has not been previously investigated in Africa. The study was conducted in Kenya, and involved participants at clinical high-risk (CHR) for psychosis (n = 268) and controls (n = 251), aged 15–25 years. CHR status was estimated using the Structured Interview of Psychosis-Risk Syndromes (SIPS) and the Washington Early Psychosis Center Affectivity and Psychosis (WERCAP) Screen. Student’s t-tests were used to assess group differences on the Temperament and Character Inventory (TCI). Neurocognitive functioning, stress severity, and substance use were correlated with the TCI, correcting for psychosis severity. CHR participants were more impulsive (ie, higher novelty seeking [NS]) and asocial (ie, lower reward dependence) than controls. They were also more schizotypal (ie, high self-transcendence [ST] and lower self-directedness [SD] and cooperativeness [CO] than controls). CO was related to logical reasoning, abstraction, and verbal memory. Stress severity correlated with high HA and schizotypal character traits. Lifetime tobacco use was related to NS, and lifetime marijuana use to high NS, low SD and high ST. Temperament and character of Kenyan CHR youth is similar to that observed in schizophrenia. Psychosis risk in Kenya is associated with impulsive, asocial, and schizotypal traits. CHR adolescents and young adults with schizophrenia-specific personality traits may be most at risk for developing a psychotic disorder and to require early intervention to improve outcomes.

Contribution of executive functions to eating behaviours in obesity and eating disorders

BACKGROUND

Patients with eating disorders (ED) or obesity show difficulties in tasks assessing decision-making, set-shifting abilities and central coherence.

AIMS

The aim of this study was to explore executive functions in eating and weight-related problems, ranging from restricting types of ED to obesity.

METHOD

Two hundred and eighty-eight female participants (75 with obesity; 149 with ED: 76 with restrictive eating, 73 with bingeing-purging symptoms; and 64 healthy controls) were administered the Wisconsin Card Sorting Test, the Iowa Gambling Task, and the Group Embedded Figures Test to assess set-shifting, decision-making and central coherence, respectively.

RESULTS

Participants with either obesity or ED performed poorly on tests measuring executive functioning compared with healthy controls, even after controlling for age and intelligence. Both participants with obesity and participants with ED showed a preference for global information processing.

CONCLUSIONS

The findings suggest that treatments for obesity and ED would benefit from addressing difficulties in cognitive functioning, in addition to the more evident clinical symptoms related to eating, body weight and shape.

Medical Complications of Eating Disorders in Youth

Eating disorders affect a significant number of individuals across the life span and are found among all demographic groups (including all genders, socioeconomic statuses, and ethnicities). They can cause malnutrition, which can have significant effects on every organ system in the body. Cardiovascular complications are particularly dangerous and cause eating disorders to have the highest mortality rate of all mental illnesses. This article outlines the medical assessment and treatment of malnutrition due to disordered eating.

Inflexibility as a Vulnerability to Depression: A Systematic Qualitative Review

The study of vulnerabilities to depression typically identifies factors that are thought to be universally maladaptive or adaptive. In contrast, researchers recently have theorized that the ability to flexibly engage in different thoughts and behaviors that fit situational demands may be most indicative of psychological health. We review empirical evidence from 147 studies reporting associations between five components of flexibility (set-shifting, affective set-shifting, cardiac vagal control, explanatory flexibility, and coping flexibility) and depression and classify studies according to strength of study design. Evidence from correlational and case-controlled studies suggests cross-sectional relationships, but few prospective studies have been conducted. We discuss limitations of existing studies, identify new directions for programmatic research, and discuss implications that flexibility has for the prevention and treatment of depression.

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.

Psychometric properties of the Greek TCI-R and its clinical correlates: schizotypy and the self-regulation of affective and cognitive functioning

Background. The revised Temperament and Character Inventory (TCI-R) measures Cloninger’s psychobiological model of personality. The average effects of individual temperament and character traits have been associated with schizotypy and with impaired regulation of affect and cognition. We extended prior research by testing predictions about the association of specific multidimensional configurations of temperament and character traits on schizotypy, affect balance, and self-perceived cognitive functioning.

Method. A well-educated sample of native Greeks (N = 483), completed a new Greek translation of the TCI-R, as well as the Schizotypal Personality Questionnaire (SPQ), the Positive/Negative Affect Schedule (PANAS) and the Cognitive Failures Questionnaire (CFQ). The factor structure of the TCI-R was examined with exploratory and confirmatory tests. Associations between reported measures were examined with correlational and regression analyses.

Results. The TCI-R had good psychometric properties as expected from studies in other countries. As predicted, specific configurations of temperament and character were associated with schizotypy, negative affect balance, and cognitive lapses. The “Borderline/Explosive temperament” (high Novelty Seeking, high Harm Avoidance, low Reward Dependence), “Schizotypal/Disorganized character” (low Self-directedness, low Cooperativeness, high Self-transcendence), and “Low Ego Strength/Fragile” profile (high Harm Avoidance, low Persistence, low Self-Directedness) were each strongly associated with higher stereotypy, negative affect balance (low positive affect and high negative affect), and subjective cognitive lapses compared to their contrast groups.

Discussion. Multidimensional TCI profiles are strongly related to individual differences in schizotypy and self-reported regulation of affect and cognition. The Greek translation of the TCI-R is psychometrically sound and useful for clinical assessment and research.

Are There Differences in Central Coherence and Set Shifting Across the Subtypes of Anorexia Nervosa?: A Systematic Review

Anorexia nervosa (AN) has been associated with weaknesses in central coherence and set shifting. In this line, it has been proposed to directly address these neuropsychological features in treatment (e.g., cognitive remediation therapy). It is not clear, however, whether the 2 subtypes of AN, the restricting (AN-R) and bingeing/purging (AN-BP) type, have the same amount of problems in these domains. A systematic search of the literature was conducted, using the databases Web of Science and PubMed, looking for studies on the comparison of AN-R and AN-BP in performing central coherence/set-shifting tasks. Notably, very few authors describe the results of a direct comparison of the performance of patients with AN-R and AN-BP. In summary, the available indications for possible group differences are not strong enough to draw definitive conclusions.

Neuropsychological function in patients with anorexia nervosa or bulimia nervosa

OBJECTIVE

This study explored the neuropsychological performance of patients diagnosed with anorexia nervosa (AN) or bulimia nervosa (BN) compared with healthy controls (HCs). An additional aim was to investigate the effect of several possible mediators on the association between eating disorders (EDs) and cognitive function.

METHOD

Forty patients with AN, 39 patients with BN, and 40 HCs who were comparable in age and education were consecutively recruited to complete a standardized neuropsychological test battery covering the following cognitive domains: verbal learning and memory, visual learning and memory, speed of information processing, visuospatial ability, working memory, executive function, verbal fluency, attention/vigilance, and motor function.

RESULTS

The AN group scored significantly below the HCs on eight of the nine measured cognitive domains. The BN group also showed inferior performance on six cognitive domains. After adjusting for possible mediators, the nadir body mass index (lowest lifetime BMI) and depressive symptoms explained all findings in the BN group. Although this adjustment reduced the difference between the AN and HC groups, the AN group still performed worse than the HCs regarding verbal learning and memory, visual learning and memory, visuospatial ability, working memory, and executive functioning.

DISCUSSION

Patients with EDs scored below the HCs on several cognitive function measures, this difference being most pronounced for the AN group. The nadir BMI and depressive symptoms had strong mediating effects. Longitudinal studies are needed to identify the importance of weight restoration and treatment of depressive symptoms in the prevention of a possible cognitive decline.

Decision making, central coherence and set-shifting: a comparison between Binge Eating Disorder, Anorexia Nervosa and Healthy Controls

BACKGROUND

Several studies have investigated the cognitive profile in patients with Anorexia Nervosa (AN) and Bulimia Nervosa (BN); on the contrary few studies have evaluated it in patients with Binge Eating Disorder (BED). The purpose of this study was to compare decision making, central coherence and set-shifting between BED and AN patients.

METHODS

A battery of neuropsychological tests including the Iowa Gambling Task (IGT), the Rey-Osterrieth Complex Figure Test (RCFT), the Wisconsin Card Sorting Test (WCST), the Trial Making Task (TMT) and the Hayling Sentence Completion Task (HSCT) were administered in a sample of 135 women (45 AN, 45 BED, 45 Healthy Controls [HC]). Furthermore, Beck Depression Inventory (BDI) was administered to evaluate depressive symptoms. Years of education, age, Body Mass Index (BMI) and depression severity were considered as covariates in statistical analyses.

RESULTS

BED and AN patients showed high rates of cognitive impairment compared to HC on the domains investigated; furthermore, the cognitive profile of BED patients was characterised by poorer decision making and cognitive flexibility compared to patients with AN. Cognitive performance was strongly associated with depressive symptoms.

CONCLUSIONS

In the present sample, two different neurocognitive profiles emerged: a strong cognitive rigidity and a central coherence based on the details was predominant in patients with AN, while a lack of attention and difficulty in adapting to changes in a new situation seemed to better describe patients with BED. The knowledge of the different cognitive profiles of EDs patients may be important for the planning their psychotherapeutic intervention.

Set-shifting ability across the spectrum of eating disorders and in overweight and obesity: a systematic review and meta-analysis

BACKGROUND

In this meta-analysis we review the findings from neuropsychological studies on set-shifting in people with eating disorders (EDs) or overweight/obesity.

METHOD

Four databases (PubMed, PsycINFO, PSYNDEX and Web of Science) were searched for eligible studies. Effect sizes (ESs) were pooled using random-effects models. Moderator analyses were conducted for ED and overweight/obese subgroups, adult/adolescent samples and measures of set-shifting.

RESULTS

Sixty-four studies with a total of 1825 ED patients [1394 anorexia nervosa (AN), 376 bulimia nervosa (BN) and 55 binge eating disorder (BED)] and 10 studies with a total of 449 overweight/obese individuals were included. The meta-analysis revealed a small to medium ES for inefficient set-shifting across all three ED diagnoses (Hedges' g = -0.45). Subgroup analyses yielded small to medium ESs for each ED subtype (g = -0.44 for AN, -0.53 for BED, -0.50 for BN), which did not differ significantly. There was a medium ES for restricting type AN (ANR; g = -0.51) but no significant ES for binge/purge type AN (AN/BP; g = -0.18). A medium ES was found across obesity studies (g = -0.61). The ES across overweight studies was not significant (g = -0.07). Adult samples did not differ from adolescent samples in either ED or overweight/obesity studies. The different set-shifting measures were associated with largely varying ESs.

CONCLUSIONS

The meta-analysis provides strong support that inefficient set-shifting is a salient neuropsychological phenomenon across ED subtypes and obesity, but is less prominent in AN/BP and overweight. Compulsivity seems to be a common underlying factor supporting a dimensional and transdiagnostic conceptualization of EDs and obesity.

Clinical investigation of set-shifting subtypes in anorexia nervosa

While evidence continues to accumulate on the relevance of cognitive inflexibility in anorexia nervosa (AN), its clinical correlates remain unclear. We aimed at examining the relationship between set-shifting and clinical variables (i.e., eating psychopathology, depression, and personality) in AN. Ninety-four individuals affected by AN and 59 healthy controls (HC) were recruited. All participants were assessed using: Eating Disorders Inventory-2 (EDI-2), Temperament and Character Inventory (TCI), Beck Depression Inventory (BDI), and Wisconsin Card Sorting Test (WCST). The AN group scored worse than HCs on set-shifting. According to their neuropsychological performances, AN patients were split into two groups corresponding to poor (N=30) and intact (N=64) set-shifting subtypes. Interoceptive awareness, impulse regulation, and maturity fears on the EDI-2 and depression on the BDI differed across all groups (HC, intact, and poor set-shifting subtype). Self-directedness on the TCI differed significantly among all groups. Cooperativeness and reward dependence differed instead only between HC and AN poor set-shifting subtype. After controlling for depression, only interoceptive awareness remained significant with reward dependence showing a trend towards statistical significance. These findings suggest that multiple clinical variables may be correlated with set-shifting performances in AN. The factors contributing to impaired cognitive inflexibility could be more complex than heretofore generally considered.

Impulsiveness in patients with bulimia nervosa: electrophysiological evidence of reduced inhibitory control

OBJECTIVES

Bulimia nervosa (BN) is associated with a deficit of self-regulatory control and impulsivity. The present study aimed to clarify whether an impaired inhibitory control due to hyperarousal underlies impulsivity in BN subjects.

METHODS

Event-related potentials (ERPs) were recorded in 17 female patients with BN and 17 healthy controls during a three-tone oddball task. ERP components related to inhibition of irrelevant distractor stimuli, as well as effortful processing, were analyzed. Standardized low-resolution electromagnetic tomography (sLORETA) was used to assess ERP source activity.

RESULTS

Compared to healthy controls, BN patients showed reduced amplitude and shorter latency of the N200 (N2), increased amplitude and shorter latency of the target slow wave (SW), and higher amplitude of the P300 for distractor stimuli (P3a) and for targets (P3b). sLORETA showed the following: (1) higher activity of the P3a generators in the left parietal cortex, bilateral precuneus and right frontal and anterior cingulate for distractor stimuli and (2) lower activity of the SW generators in the left medial frontal gyrus, bilateral superior frontal, anterior cingulate and cuneus for target stimuli. The reduction of the N2 latency was associated with the Barratt scores for impulsiveness.

CONCLUSIONS

The observed electrophysiological abnormalities suggest a condition of hyperarousal, with impaired suppression of irrelevant stimuli due to abnormal cortical activation and reduced signal-to-noise ratio. Our findings point to functional abnormalities within a neural system that subserves attention and self-regulatory control, which may contribute to impulsive behaviors in BN.

Acute glucocorticoid effects on response inhibition in borderline personality disorder

INTRODUCTION

Growing evidence suggests inhibition dysfunctions in borderline personality disorder (BPD). Moreover, abnormalities in hypothalamic-pituitary-adrenal (HPA) axis functioning have also been found in BPD patients. In healthy individuals, response inhibition has been sensitive to acute stress, and previous research indicates that effects mediated by the HPA axis become particularly apparent when emotional stimuli are processed. This study aimed to explore the influence of acute hydrocortisone administration on response inhibition of emotional stimuli in BPD patients compared to healthy control participants.

METHODS

After a single administration of 10mg hydrocortisone or placebo, 32 female BPD patients and 32 healthy female participants performed an adapted emotional go/no-go paradigm to assess response inhibition for emotional face stimuli in a cross-over study.

RESULTS

Acute cortisol elevations decreased the reaction times to target stimuli in both BPD patients and healthy controls. Patients and controls did not differ in task performance; however, BPD patients with comorbid posttraumatic stress disorder (PTSD) displayed longer reaction times than patients without PTSD. In contrast, the occurrence of comorbid eating disorder had no significant impact on go/no-go performance. No significant interaction effect between the treatment condition and the emotional valence of the face stimuli was found.

CONCLUSIONS

Acute hydrocortisone administration enhances response inhibition of face stimuli in BPD patients and healthy controls, regardless of their emotional valence. Our results agree with the suggestion that moderate cortisol enhancement increases the inhibition of task-irrelevant distracters.

The neuropsychological profile of children at high risk of developing an eating disorder

BACKGROUND

There is a large body of evidence indicating that eating disorders (EDs) are characterized by particular neuropsychological profiles. We aimed to further explore whether impairments in neuropsychological functioning previously found in ED groups are present prior to onset, or are secondary to the disorder. Method This is the first study to explore neuropsychological functioning in children born to a mother with a lifetime ED, who are therefore at high risk of developing an ED, in a large cohort sample. We investigated intelligence and attention at age 8 years (n = 6201) and working memory (WM) and inhibition at age 10 years (6192) in children who are at high risk of developing an ED, compared to children who are not.

RESULTS

The children of women with lifetime anorexia nervosa (AN) showed high full-scale and performance IQ, increased WM capacity, better visuo-spatial functioning, and decreased attentional control. The children of women with lifetime bulimia nervosa (BN) showed comparatively poor visuo-spatial functioning.

CONCLUSIONS

Our findings suggest that high intelligence, increased WM capacity and impaired attentional control might be intermediate phenotypes on the pathway between genetic vulnerability and the development of an ED.

The role of impulsivity, inattention and comorbid ADHD in patients with bulimia nervosa

Introduction

Little is known about the contribution of impulsivity, inattention and comorbid attention deficit/hyperactivity disorder (ADHD) in the development and maintenance of bulimia nervosa (BN). In particular, their specific contribution to disordered eating symptoms and whether they have additive effects to the general psychopathological burden remains unclear.

Methods

Fifty-seven female patients seeking treatment for BN and 40 healthy controls completed diagnostic questionnaires and interviews that investigated: a) ADHD, b) impulsivity, c) eating disorders and d) general psychopathology. Attentional processes and impulsivity were assessed by a comprehensive computer-based neuropsychological battery.

Results

Twenty-one percent of patients with BN met the clinical cut-off for previous childhood ADHD compared to 2.5% of healthy controls. Adult ADHD according to DSM IV was also more prevalent in patients with BN, with an odds ratio of 4.2. Patients with BN and previous childhood ADHD were more impulsive and inattentive than patients with BN alone. These patients also displayed more severely disordered eating patterns and more general psychopathological symptoms compared with those without ADHD. Severity of eating disorder symptoms was better explained by inattentiveness than by either impulsivity or hyperactivity.

Discussion

Our data suggest an elevated rate of former childhood and current ADHD-symptoms in treatment-seeking patients with BN. Stronger impulsivity and inattention associated with more severe neuropsychological deficits and eating disorder symptoms indicate an additive risk that is clinically relevant for these patients. Thus, clinicians should identify comorbid patients who might profit from additional ADHD-specific treatments.

Personality, clinical features, and test instructions can affect executive functions in Eating Disorders

Cognitive deficits in Eating Disorders have been related to the executive function domain. Yet, to date, only few works investigated the relationship between neuropsychological and clinical issues, and these studies were separately conducted either on Anorexia Nervosa (AN) or Bulimia Nervosa (BN). In this study, three groups of AN, BN and matched controls were administered the Trail Making Test, the Wisconsin Card Sorting Test, and the Hayling Sentence Completion Test, in addition to personality and clinical assessments (Temperament and Character Inventory, SCL-90-R, EDI-2). Results from AN indicated a relationship between cognitive rigidity and fixed psychological traits. Conversely, BN showed broader correlations among slowness, inhibition, and psychopathology-state indexes, confirming the clear relation published in the literature. We also hypothesize that task peculiar characteristics can affect high-order attentional activities in Eating Disorders. In fact, these patients do not differ from controls when the examiner provides overt instruction and run-in examples, but they can find serious difficulties when the correct rule is to be derived and modified from feedbacks during the test, as in the Wisconsin Card Sorting Test. Perfectionist stable traits support this hypothesis, especially in AN, as excessive cognitive control can either improve or damage set-shifting and decision-making procedures.

Motor inhibition and cognitive flexibility in eating disorder subtypes

Anorexia Nervosa (AN) and Bulimia Nervosa (BN) are complex Eating Disorders (EDs). Even if are considered two different diagnostic categories, they share clinical relevant characteristics. The evaluation of neurocognitive functions, using standardized neuropsychological assessment, could be a interesting approach to better understand differences and similarities between diagnostic categories and clinical subtypes in EDs thus improving our knowledge of the pathophisiology of EDs spectrum. This study explored cognitive flexibility and motor inhibition in patients with AN considering both Restricter and Binge/Purge subtypes, patients with BN and healthy comparisons subjects (HC). Intra-Extra Dimentional Set shifting Test and Stop Signal Task, selected from CANTAB battery, were administered to analyzed set-shifting and motor inhibition respectively. AN patients showed a deficient motor inhibition compared to HC, while no evidence for impaired motor inhibition was found in BN patients; a significant relationship between commission errors in the Stop Signal Task and attentional impulsiveness was found. Moreover, no difference in set-shifting abilities was found comparing all clinician groups and HC. So our results indicated no cognitive impairment in these two cognitive functions in BN patients, while AN and BN showed different performances in motor inhibition. A similar cognitive profile was found in other obsessive compulsive spectrum disorders. Finally, the paper suggests a new interactive approach for the study of cognitive profile in psychiatric disorders; it might be more useful since it is more closely related to the executive functions complexity.

Neurocognition in bulimic eating disorders: a systematic review

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

OBJECTIVE

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

METHOD

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

RESULTS

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

CONCLUSION

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