BackgroundPeople with eating disorders (ED) frequently present with inflexible behaviours, including eating related issues which contribute to the maintenance of the illness. Small scale studies point to difficulties with cognitive set-shifting as a basis. Using larger scale studies will lend robustness to these data.Methodology/Principal Findings542 participants were included in the dataset as follows: Anorexia Nervosa (AN) n = 171; Bulimia Nervosa (BN) n = 82; Recovered AN n = 90; Healthy controls (HC): n = 199. All completed the Wisconsin Card Sorting Task (WCST), an assessment that integrates multiple measurement of several executive processes concerned with problem solving and cognitive flexibility. The AN and BN groups performed poorly in most domains of the WCST. Recovered AN participants showed a better performance than currently ill participants; however, the number of preservative errors was higher than for HC participants.Conclusions/SignificanceThere is a growing interest in the diagnostic and treatment implications of cognitive flexibility in eating disorders. This large dataset supports previous smaller scale studies and a systematic review which indicate poor cognitive flexibility in people with ED.

BackgroundAnorexia nervosa (AN) is a severe mental illness. Drug treatments are not effective and there is no established first choice psychological treatment for adults with AN. Neuropsychological studies have shown that patients with AN have difficulties in cognitive flexibility: these laboratory based findings have been used to develop a clinical intervention based on Cognitive Remediation Therapy (CRT) which aims to use cognitive exercises to strengthen thinking skills.Aims1) To conduct a preliminary investigation of CRT in patients with AN 2) to explore whether cognitive training improves performance in set shifting tasks 3) to explore whether CRT exercises are appropriate and acceptable to AN patients 4) to use the data to improve a CRT module for AN patients.MethodsIntervention was comprised of ten 45 minute sessions of CRT. Four patients with AN were assessed before and after the ten sessions using five set shifting tests and clinical assessments. At the end, each patient wrote a letter providing feedback on the intervention.ResultsPost intervention, three of the five set shifting assessments showed a moderate to large effect size in performance and two showed a large effect size in performance, both indicative of improved flexibility. Patients were aware of an improvement in their cognitive flexibility qualitative feedback was generally positive towards CRT.DiscussionThis preliminary study suggests that CRT changed performance on flexibility tasks and may be beneficial for acute, treatment resistant patients with AN. Feedback gathered from this small case series has enabled modification of the intervention for a future larger study, for example, by linking exercises with real life behavioural tasks and including exercises that encourage global thinking.ConclusionThis exploratory study has produced encouraging data supporting the use of CRT in patients with AN: it has also provided insight into how the module should be tailored to maximise its effectiveness for people with acute AN.

ObjectivesThe aim of this study was to explore cognitive flexibility in a large dataset of people with Eating Disorders and Healthy Controls (HC) and to see how patient characteristics (body mass index [BMI] and length of illness) are related to this thinking style.MethodsA dataset was constructed from our previous studies using a conceptual shift test - the Brixton Spatial Anticipation Test. 601 participants were included, 215 patients with Anorexia Nervosa (AN) (96 inpatients; 119 outpatients), 69 patients with Bulimia Nervosa (BN), 29 Eating Disorder Not Otherwise Specified (EDNOS), 72 in long-term recovery from AN (Rec AN) and a comparison group of 216 HC.ResultsThe AN and EDNOS groups had significantly more errors than the other groups on the Brixton Test. In comparison to the HC group, the effect size decrement was large for AN patients receiving inpatient treatment and moderate for AN outpatients.ConclusionsThese findings confirm that patients with AN have poor cognitive flexibility. Severity of illness measured by length of illness does not fully explain the lack of flexibility and supports the trait nature of inflexibility in people with AN.

Difficulty identifying and expressing feelings could be related to this diminished drive for social pleasure. Tackling these interpersonal maintaining factors in treatment is likely to be a worthwhile endeavor.

This experimental study supports self report studies showing people with AN attenuate emotional expression and avoid negative affect. Such behavior may affect social interaction and contribute to the maintenance of the disorder.