title: Cognitive flexibility and clinical severity in eating disorders.
abstract: OBJECTIVE
  The 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.
  
  
  METHODS
  A 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.
  
  
  RESULTS
  The 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.
  
  
  CONCLUSIONS
  These 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.
authors.affiliation: Institute of Psychiatry, Psychological Medicine, King's College London, London, United Kingdom. kate.tchanturia@kcl.ac.uk
authors.forename: Kate
authors.initials: K
authors.lastname: Tchanturia
authors.forename: Amy
authors.initials: A
authors.lastname: Harrison
authors.forename: Helen
authors.initials: H
authors.lastname: Davies
authors.forename: Marion
authors.initials: M
authors.lastname: Roberts
authors.forename: Anna
authors.initials: A
authors.lastname: Oldershaw
authors.forename: Michiko
authors.initials: M
authors.lastname: Nakazato
authors.forename: Daniel
authors.initials: D
authors.lastname: Stahl
authors.forename: Robin
authors.initials: R
authors.lastname: Morris
authors.forename: Ulrike
authors.initials: U
authors.lastname: Schmidt
authors.forename: Janet
authors.initials: J
authors.lastname: Treasure
mesh_terms: D000328:Adult; D015992:Body Mass Index; D003071:Cognition; D001068:Feeding and Eating Disorders / Q000473:pathology* / Q000523:psychology*; D006801:Humans; D012720:Severity of Illness Index