Attention networks in adolescent anorexia nervosa

Executive dysfunction in eating disorders: Relationship with clinical features

Eating disorders (ED) are severe mental disorders that may result in significant functional impairment and disability. Neuropsychological studies have consistently found impaired executive function (EF) among ED patients. EF is particularly involved in fundamental skills of daily living and in behavioral and emotional regulation. In this study, impairment of executive functioning is investigated in patients with eating disorders and the associations with clinical features and clinical subtypes are analyzed.

METHOD

75 female patients (m = 22.01 years, sd = 9.15) with eating disorder (43 restrictive anorexia, 30 binge-eating anorexia and 13 bulimia nervosa) and 37 healthy controls (m = 18.54 years, sd = 4.21) were included in the study. An extensive assessment of executive function domains (verbal fluency, set shifting, attention span, selective attention, working memory, inhibitory control and processing speed) was carried out in both groups. Clinical scales for food intake restriction, binge-eating/purging, depression, anxiety and impulsivity were also administered and correlated with scores on executive function tests.

RESULTS

Patients with an ED had significantly lower scores than healthy controls in performance of several executive function tests, particularly in set shifting, interference control and processing speed (p < .01, in all three domains). Executive function impairment was related to anxious, depressive and eating disorder symptoms (p < .05), regardless of clinical subtype.

CONCLUSIONS

Executive function impairment in eating disorders is associated with greater ED symptomatic severity and might involve a negative treatment outcome. Therefore, cognitive remediation techniques should probably be considered in a number of severe patients with ED.

Altered processing of conflicting body representations in women with restrictive anorexia nervosa

Cognitive and affective impairments in processing body image have been observed in patients with Anorexia Nervosa (AN) and may induce the hypercontrolled and regulative behaviors observed in this disorder. Here, we aimed to probe the link between activation of body representations and cognitive control by investigating the ability to resolve body-related representational conflicts in women with restrictive AN and matched healthy controls (HC). Participants performed a modified version of the Flanker task in which underweight and overweight body images were presented as targets and distractors; a classic version of the task, with letters, was also administered as a control. The findings indicated that performance was better among the HC group in the task with bodies compared to the task with letters; however, no such facilitation was observed in AN patients, whose overall performance was poorer than that of the HC group in both tasks. In the task with body stimuli, performance among patients with AN was the worst on trials presenting underweight targets with overweight bodies as flankers. These results may reflect a dysfunctional association between the processing of body-related representations and cognitive control mechanisms that may aid clinicians in the development of optimal individualized treatments.

The perception of food size and food shape in anorexia nervosa

Visual perception of food size and shape in anorexia nervosa (AN) is an understudied topic, notwithstanding its relevance in approaching food, key-element in weight restoration. In addition, it is unclear how visual perception in AN is related to the age and the duration of illness. Here, we compared patients with AN to healthy controls (HCs) on their spatial resolution, biases in perceived food size, and holistic processing of food shape. A total of 122 participants were enrolled: 48 adolescents (27 AN and 21 HCs) and 74 adults (33 AN and 41 HCs). Participants at two academic sites (Israel and Italy) completed measures of psychopathology and experiments measuring visual resolution (Just Noticeable Difference), biases in food-size perception (Points of Subjective Equality), and holistic processing of food shape (indicated by the height-width illusion). Adolescents and adults with AN differed in the duration of illness and body mass index but showed comparable eating psychopathology and body measures. Patients with AN showed preserved visual resolution but distorted perception of food size, perceiving food as bigger than non-food objects, in both age groups. Patients with AN, both adolescents and adults, also processed food stimuli in a more analytic fashion, and were immune to the height-width illusion. The preserved perception of non-food stimuli in AN coupled with biases in food-size perception and in analytic processing of food shape highlight patients' real-world difficulties in approaching food. Future treatments on AN may consider taking these differences into account.

The relationship between attention and avoidance coping in anorexia nervosa: functional magnetic resonance imaging study

BACKGROUND

Numerous studies have demonstrated attentional control difficulties and high avoidance coping in patients with anorexia nervosa. Attention is a critical coping resource because it enables individuals to demonstrate self-control and complete goal-directed behaviours.

AIMS

We aimed to examine whether attentional control difficulty is related to high avoidance coping, and investigate the neural underpinnings of attentional control difficulties in individuals with anorexia nervosa.

METHOD

Twenty-three patients with anorexia nervosa and 17 healthy controls completed questionnaires that assessed attention and coping, and underwent functional magnetic resonance imaging while performing a go/no-go task.

RESULTS

Patients with anorexia nervosa showed weaker attentional control, higher omission error rates and higher avoidance coping compared with healthy controls. Attentional control difficulty was associated with higher avoidance coping in both groups. Functional magnetic resonance imaging analysis showed less deactivation in regions representing internal mental processing, such as the praecuneus, cuneus and left lingual gyrus, during the no-go condition. Moreover, weakened deactivation of the left lingual gyrus was associated with higher commission error rate in the anorexia nervosa group.

CONCLUSIONS

Our results suggest that patients with anorexia nervosa may have difficulty in maintaining attention to external ongoing events because of disturbance from internal self-related thought, and support the notion that attentional control difficulties underlie the frequent use of avoidance coping in anorexia nervosa.

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.

Verifying Feighner's Hypothesis; Anorexia Nervosa Is Not a Psychiatric Disorder

Mental causation takes explanatory priority over evolutionary biology in most accounts of eating disorders. The evolutionary threat of starvation has produced a brain that assists us in the search for food and mental change emerges as a consequence. The major mental causation hypothesis: anxiety causes eating disorders, has been extensively tested and falsified. The subsidiary hypothesis: anxiety and eating disorders are caused by the same genotype, generates inconsistent results because the phenotypes are not traits, but vary along dimensions. Challenging the mental causation hypothesis in Feighner et al. (1972) noted that anorexic patients are physically hyperactive, hoarding for food, and they are rewarded for maintaining a low body weight. In 1996, Feighner's hypothesis was formalized, relating the patients' behavioral phenotype to the brain mechanisms of reward and attention (Bergh and Södersten, 1996), and in 2002, the hypothesis was clinically verified by training patients how to eat normally, thus improving outcomes (Bergh et al., 2002). Seventeen years later we provide evidence supporting Feighner's hypothesis by demonstrating that in 2012, 20 out of 37 patients who were referred by a psychiatrist, had a psychiatric diagnosis that differed from the diagnosis indicated by the SCID-I. Out of the 174 patients who were admitted in 2012, most through self-referral, there was significant disagreement between the outcomes of the SCID-I interview and the patient's subjective experience of a psychiatric problem in 110 of the cases. In addition, 358 anorexic patients treated to remission scored high on the Comprehensive Psychopathological Rating Scale, but an item response analysis indicated one (unknown) underlying dimension, rather than the three dimensions the scale can dissociate in patients with psychiatric disorders. These results indicate that psychiatric diagnoses, which are reliable and valid in patients with psychiatric disorders, are less well suited for patients with anorexia. The results are in accord with the hypothesis of the present Research Topic, that eating disorders are not always caused by disturbed psychological processes, and support the alternative, clinically relevant hypothesis that the behavioral phenotype of the patients should be addressed directly.

Set-shifting in adolescents with weight-restored anorexia nervosa and their unaffected family members

Set-shifting difficulties have been suggested to underlie rigid and inflexible thinking in patients with anorexia nervosa (AN). Studies reported set-shifting deficiencies in adults with AN and also in their unaffected family members, suggesting that set-shifting deficits are heritable in AN. Surprisingly, studies failed to show set-shifting difficulties in adolescents with AN. If set-shifting difficulties are heritable, it is not clear why they are absent in adolescents with AN. The current study aimed to elucidate this discrepancy by assessing several components of set-shifting in adolescents with weight-restored AN (WR-AN) and their unaffected parents and siblings. Twenty-one families that include an adolescent who was diagnosed with AN prior to weight restoration (N = 19), an unaffected parent (N = 18), and an unaffected sibling (N = 20) were recruited. Additionally, 28 healthy control families were recruited and included an age-matched adolescent (N = 27), a parent (N = 26), and a sibling (N = 17). Visual-motor set-shifting, verbal set-shifting, and set-shifting clean of inhibition were assessed using the Delis-Kaplan Executive Function System. The results revealed intact set-shifting in parents and siblings of adolescents with WR-AN. Surprisingly, the results revealed superior visual-motor and verbal set-shifting in adolescents with WR-AN compared to age-matched controls. However, when controlling for inhibition abilities, poorer set-shifting was revealed in adolescents with WR-AN. The results suggest that superior inhibition abilities in adolescents with WR-AN may compensate for their set-shifting deficiencies. The study emphasizes the importance of controlling for inhibition abilities when assessing neurocognitive functioning in adolescents with AN. Furthermore, the study does not support the notion that set-shifting deficits are heritable in adolescent AN.

Resting-state connectivity within and across neural circuits in anorexia nervosa

INTRODUCTION

Obsessional thoughts and ritualized eating behaviors are characteristic of Anorexia Nervosa (AN), leading to the common suggestion that the illness shares neurobiology with obsessive-compulsive disorder (OCD). Resting-state functional connectivity MRI (rs-fcMRI) is a measure of functional neural architecture. This longitudinal study examined functional connectivity in AN within the limbic cortico-striato-thalamo-cortical (CSTC) loop, as well as in the salience network, the default mode network, and the executive control network (components of the triple network model of psychopathology).

METHODS

Resting-state functional connectivity MRI scans were collected in unmedicated female inpatients with AN (n = 25) and healthy controls (HC; n = 24). Individuals with AN were scanned before and after weight restoration and followed for one month after hospital discharge. HC were scanned twice over the same timeframe.

RESULTS

Using a seed-based correlation approach, individuals with AN had increased connectivity within the limbic CSTC loop when underweight, only. There was no significant association between limbic CSTC connectivity and obsessive-compulsive symptoms or prognosis. Exploratory analyses of functional network connectivity within the triple network model showed reduced connectivity between the salience network and left executive control network among AN relative to HC. These abnormalities persisted following weight restoration.

CONCLUSIONS

The CSTC findings suggest that the neural underpinnings of obsessive-compulsive symptoms may differ from those of OCD. The inter-network abnormalities warrant examination in relation to illness-specific behaviors, namely abnormal eating behavior. This longitudinal study highlights the complexity of the neural underpinnings of AN.