K. Tchanturia

Central coherence in eating disorders: a systematic review

BACKGROUNDnThis review systematically appraised the research evidence for local versus global information processing to test the hypothesis that people with eating disorders (ED) had weak central coherence.nnnMETHODnSearches on Medline, EMBASE, PsycINFO and ISI Web of Science databases were conducted in November 2006 and subsequently updated in September 2007. Each search was conducted in two steps: (1) neuropsychological tasks measuring central coherence and (2) words related to cognitive functioning in eating disorders. Data were summarized in a meta-analysis if the number of studies for a given test was >5.nnnRESULTSnData were extracted from 16 studies. Meta-analyses were conducted for four tasks obtaining moderate effect sizes. The majority of studies found global processing difficulties across the ED spectrum. The results are less clear regarding local processing.nnnCONCLUSIONSnPeople with ED have difficulties in global processing. It is less certain as to whether they have superior local processing. Currently, there is insufficient evidence to refute the weak central coherence hypothesis.

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.

Brain-derived neurotrophic factor (BDNF) and set-shifting in currently ill and recovered anorexia nervosa (AN) patients

BACKGROUNDnStudies of patients with anorexia nervosa (AN) have shown that they do not perform well in set-shifting tasks but little is known about the neurobiological correlates of this aspect of executive function. The aim of this study was to measure serum brain-derived neurotrophic factor (BDNF) and to establish whether set-shifting difficulties are present in people with current AN and in those recovered from AN, and whether serum BDNF concentrations are correlated with set-shifting ability.nnnMETHODnSerum BDNF concentrations were measured in 29 women with current AN (AN group), 18 women who had recovered from AN (ANRec group) and 28 age-matched healthy controls (HC group). Set-shifting was measured using the Wisconsin Card Sorting Test (WCST). Eating-related psychopathology and depressive, anxiety and obsessive-compulsive symptomatology were evaluated using the Eating Disorder Examination Questionnaire (EDEQ), the Hospital Anxiety and Depression Scale (HADS), and the Maudsley Obsessive-Compulsive Inventory (MOCI) respectively.nnnRESULTSnSerum BDNF concentrations (mean+/-s.d.) were significantly lower in the AN group (11.7+/-4.9 ng/ml) compared to the HC group (15.1+/-5.5 ng/ml, p=0.04) and also compared to the ANRec group (17.6+/-4.8 ng/ml, p=0.001). The AN group made significantly more errors (total and perseverative) in the WCST relative to the HC group. There was no significant correlation between serum BDNF concentrations and performance on the WCST.nnnCONCLUSIONSnSerum BDNF may be a biological marker for eating-related psychopathology and of recovery in AN. Longitudinal studies are needed to explore possible associations between serum BDNF concentrations, illness and recovery and neuropsychological traits.

The inability to ignore: distractibility in women with restricting anorexia nervosa

BACKGROUNDnAttentional difficulties reported in individuals with anorexia nervosa (AN) may be due to preferential processing of disease-salient stimuli at a pre-attentive or at a conscious level or to a general problem in attention. Attentional difficulties may be associated with duration of illness.nnnMETHODnFemale participants with AN (restricting subtype; n=24) and healthy comparison women (n=24) were randomly allocated to subliminal or supraliminal exposure to visual stimuli (food, neutral and aversive images) while performing the 1-back and 2-back working-memory tasks.nnnRESULTSnParticipants with AN made fewer errors than the healthy comparison group in the subliminal condition but significantly more errors in the supraliminal condition [condition x group interaction, F(1, 44)=6.82, p<0.01]: this was irrespective of stimulus type (food, neutral and aversive) and task (1-back or 2-back). The total number of errors made correlated positively with the duration of the AN for both the 1-back task (rs=0.46, p<0.05) and for the 2-back task (rs=0.53, p<0.01).nnnCONCLUSIONSnDecreased ability to concentrate in the presence of explicit distracters is a feature of AN and is associated with longer duration of illness. This phenomenon could be addressed in psychological interventions.

Diminished facial emotion expression and associated clinical characteristics in Anorexia Nervosa

This study aimed to investigate emotion expression in a large group of children, adolescents and adults with Anorexia Nervosa (AN), and investigate the associated clinical correlates. One hundred and forty-one participants (AN=66, HC= 75) were recruited and positive and negative film clips were used to elicit emotion expressions. The Facial Activation Coding system (FACES) was used to code emotion expression. Subjective ratings of emotion were collected. Individuals with AN displayed less positive emotions during the positive film clip compared to healthy controls (HC). There was no significant difference between the groups on the Positive and Negative Affect Scale (PANAS). The AN group displayed emotional incongruence (reporting a different emotion to what would be expected given the stimuli, with limited facial affect to signal the emotion experienced), whereby they reported feeling significantly higher rates of negative emotion during the positive clip. There were no differences in emotion expression between the groups during the negative film clip. Despite this individuals with AN reported feeling significantly higher levels of negative emotions during the negative clip. Diminished positive emotion expression was associated with more severe clinical symptoms, which could suggest that these individuals represent a group with serious social difficulties, which may require specific attention in treatment.

Computerised analysis of facial emotion expression in eating disorders

Background Problems with social-emotional processing are known to be an important contributor to the development and maintenance of eating disorders (EDs). Diminished facial communication of emotion has been frequently reported in individuals with anorexia nervosa (AN). Less is known about facial expressivity in bulimia nervosa (BN) and in people who have recovered from AN (RecAN). This study aimed to pilot the use of computerised facial expression analysis software to investigate emotion expression across the ED spectrum and recovery in a large sample of participants. Method 297 participants with AN, BN, RecAN, and healthy controls were recruited. Participants watched film clips designed to elicit happy or sad emotions, and facial expressions were then analysed using FaceReader. Results The finding mirrored those from previous work showing that healthy control and RecAN participants expressed significantly more positive emotions during the positive clip compared to the AN group. There were no differences in emotion expression during the sad film clip. Discussion These findings support the use of computerised methods to analyse emotion expression in EDs. The findings also demonstrate that reduced positive emotion expression is likely to be associated with the acute stage of AN illness, with individuals with BN showing an intermediate profile.

Young people’s experience of individual Cognitive Remediation Therapy (CRT) in an inpatient eating disorder service: a qualitative study

Introduction and PurposeCurrent literature shows promising results regarding the efficacy of Cognitive Remediation Therapy for Anorexia Nervosa (AN); however, there is a paucity of studies considering the use of CRT in Young People (YP). The aim of this study was to examine YP’s experiences of individual CRT in an inpatient eating disorder unit.MethodSeventy letters following a cycle of eight individual CRT sessions were analysed using thematic analysis, adopting an inductive approach. Inter-rater reliability of findings was ensured.ResultsThe following six higher-order themes, each with lower-order themes, were identified: engaging aspects of CRT; identifying thinking skills; relevance to real-life situations; encountering personal challenges; making sense of the rational of CRT; suggestions for further improvements. YP reported enjoying CRT and described increased learning about their thinking styles and their skills from the activities undertaken during therapy. Some participants were able to apply learning outside of therapy and less frequently to difficulties related to the illness.ConclusionFeedback from patients suggests CRT is a useful intervention for YP with AN, which could facilitate their engagement in the treatment, while tackling neuropsychological processes underlying psychological symptoms of AN. Exploring participants’ experience of CRT has highlighted specific elements of the intervention perceived as beneficial by YP, and areas where adaption could be made. This will allow clinicians to further develop the intervention from a service users’ perspective, tailoring the sessions to their needs.