Cognitive impairment in patients with eating disorders was reported by the majority of studies addressing this issue. However, heterogeneous patterns of cognitive dysfunctions were observed and, in a minority of studies, no impairment was found. The present study was 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.

Attention, executive control, conditional and incidental learning were evaluated in 83 untreated female patients with BN and 77 healthy controls. Cortisol and 17β-estradiol plasma levels were assessed. Cloninger's Temperament and Character Inventory-Revised (TCI-R), the Eating Disorder Inventory-2 and the Montgomery-Asberg Depression Rating Scale were administered.

No impairment of cognitive performance was found in subjects with BN vs. healthy controls. The higher the cortisol level and “Self-directedness” scores the better the performance on conditional learning, while 17β-estradiol levels showed an opposite pattern of association; “Reward dependence” scores were associated to a worse performance on incidental learning; depressive symptomatology negatively influenced the performance on the WCST.

No cognitive impairment was found in untreated patients with BN in the explored cognitive domains. An influence of neuroendocrine, personality and clinical variables on neurocognitive functioning was found, which might explain discrepancies in literature findings.