Neurocognitive functioning in bulimia nervosa: the role of neuroendocrine, personality and clinical aspects

Background. Studies investigating neurocognitive impairment in subjects with eating disorders (EDs) have reported heterogeneous patterns of impairment and, in some instances, no dysfunction. The present study aimed to define the pattern of neurocognitive impairment in a large sample of bulimia nervosa (BN) patients and to demonstrate that neuroendocrine, personality and clinical characteristics influence neurocognitive performance in BN. Method. Attention/immediate memory, set shifting, perseveration, conditional and implicit learning were evaluated in 83 untreated female patients with BN and 77 healthy controls (HC). Cortisol and 17 beta-estradiol plasma levels were assessed. Cloninger's Temperament and Character Inventory - Revised (TCI-R), the Bulimic Investigation Test Edinburgh (BITE) and the Montgomery-Asberg Depression Rating Scale (MADRS) were administered. Results. No impairment of cognitive performance was found in subjects with BN compared with HC. Cortisol and 'Self-directedness' were associated with better performance on conditional learning whereas 17 beta-estradiol had a negative influence on this domain; 'Reward dependence' was associated with worse performance on implicit learning; and depressive symptomatology influenced performance on the Wisconsin Card Sorting Test (WCST) negatively. Conclusions. No cognitive impairment was found in untreated patients with BN. Neuroendocrine, personality and clinical variables do influence neurocognitive functioning and might explain discrepancies in literature findings.