Anorexia nervosa and bulimia have the highest mortality rates among psychiatric disorders. High dropout rates 30 to 50% stand obstacle to outcomes.

To search and to analyze articles based on studies about inpatients and outpatients dropout in AN and BN.

The search was conducted through PubMed/Medline, Lilacs, PsycINFO and Cochrane databases. The selection included all the articles about AN/BN focused on dropout. Furthermore, cited articles were included when related. The articles were fully summarized, classified and submitted to categorization.

Most of the articles came from Europe; scarce results from Latin America. dropout-rates are not significantly different between inpatients and outpatients; lower rates among adolescents. Emerging categories are discussed: socio-demographic, clinical and psychological characteristics; family; therapeutic alliance. Impulsive/compulsive behaviour is the strongest predictor explaining the higher dropout rate for AN purging-subtype. The correlation with lower educational level and family background are also supported. The correlation between depression and lower dropout risk founded by some studies was not confirmed by others. Age, previous hospitalizations, length of illness, symptoms severity, weight/BMI are emerging as not consistent predictors. Dropout is not always a negative outcome.

The common discrepant results are attributed to the difficulty in composing adequate samples and to the lack of standardization of the term “dropout”. The focus on patient characteristics in research was questioned; this tendency is changing toward to take into account the answer to treatment process. Highlights: patient's difficulty in intrapersonal relationships, the therapeutic alliance and its management to adherence and continuation of treatment.