Impaired set-shifting ability in patients with bulimia nervosa: A systematic review and meta-analysis

Introduction: Previous research has shown that there is a link between bulimia nervosa (BN) diagnosis and set-shifting disability although with some conflicting results, yet no meta-analyses have examined the BN pathology with set-shifting. The aim of the present research is to critically appraise and synthesize the literature relating to set-shifting ability in Bulimia Nervosa. Materials and Methods: Four databases (PubMed, PsycINFO, Scopus, and Google Scholar) were searched for eligible studies. The 8 selected studies contained (with 24 effect sizes) both bulimia nervosa disorder and healthy control groups, and employed at least one of the following six neuropsychological measures of set-shifting ability; Trail Making Test (TMT), Wisconsin Card Sorting Test (WCST), Brixton task (BT), Haptic Illusion Task (HIT), CatBat task (CBT), Picture Set Test (PTS); Verbal Fluency Task (VFT); Intra-Extra Dimensional Set Shifting Test (ID/ED Shift Task); and Affective Shifting Task (AST) used for meta-analyses. The outcome variable was performance on the set-shifting aspect of the task. Effect sizes (Hedges’s g) were pooled using fixed-effects models. Results: Twenty-one studies were examined with a total of 514 BN patients and 939 healthy control groups. There was a small effect of BN diagnosis on set-shifting (Hedges’s g = 0.24). Conclusion: Based on the findings, problems in set-shifting as measured by a variety of neuropsychological tasks are present in people with bulimia nervosa.