Drop-out is a serious problem in ED which remains poorly understood.

To describe socio-demographic and clinical factors associated with drop-out in order to prevent this phenomenon with individualized strategies.

A semi-structured clinical interview was administered to 92 adult out-patients attending a third level centre for ED. Measures of psychopathology (EDE12th, BDI, STAI, MINI, SCID-II) were collected to achieve diagnoses. the study population included completers (CO) and drop-outs (DO) which consist of patients that did not complete the baseline assessment Failing in Alliance (FA) and persons who Failed in Treatment (FT).

The drop-out rate is 34,8%, including 17,4% of FA and 17,4% of FT. DO were less likely to have Anorexia Nervosa at Onset and Obsessive-Compulsive Personality Disorder, while serious Depressive Symptoms, Borderline Personality Disorder and Bulimia Nervosa predicted premature attrition. After multivariate analysis only the last three remain statistically significantly. Considering the period of drop out, we found that Bulimia Nervosa and Borderline Personality Disorder were independent correlated with FA respectively (OR=5,800; 95%CI 1,574–21,368) and (OR=5,782; 95%CI 1,135–29,449). Conversely FT had a higher probability to have serious Depressive Symptoms (OR= 12,289; 95%CI 1,187–127,207).

Drop-outs in ED include two different subpopulations: failure in alliance (FA) and failure in treatment (FT) characterized by different clinical characteristics. Bulimia Nervosa and Borderline Personality Disorder were predictors of FA, whereas serious Depressive Symptoms were predictors of FT.