The aim of this study was to explore the extent of lack of insight and its components in eating disorders (EDs) and to investigate the relationship between insight and clinical and cognitive characteristics in this group.

Seventy-five participants were enrolled in the study: 25 with anorexia nervosa (AN), 15 with bulimia nervosa (BN) and 35 healthy controls (HC). Insight was assessed with a modified version of the Schedule for the Assessment of Insight for EDs (SAI-ED) and multi-dimensional scaling (MDS) analysis was used to clarify the internal structure of the scale. Neuropsychological tests included the Trail Making Test (TMT), the Brixton Test and a Verbal Fluency Task.

Only a subgroup of AN patients (24%) had severe impairment of insight. Patients with the restricting type of AN (AN-R) had poorer overall insight than patients with the binge-purge type of the disorder (AN-B/P). More of the ED patients displayed a deliberate denial of illness rather than a lack of awareness of the illness. A regression model revealed that only performance in part B of the TMT (TMT-B) was a moderate predictor of insight level. No association was found between insight and other cognitive or clinical variables.

Impaired insight is a significant feature of some ED patients. Insight in EDs seems to be partially dependent on intact mental flexibility.