Atypical eating disorders: a review

Introduction: Atypical eating disorders (AEDs), also known as eating disorders not otherwise specified (EDNOS), are established eating disorders (EDs) presenting a significant clinical severity that do not fulfill the diagnostic criteria for typical anorexia nervosa (AN) or bulimia nervosa (BN). Methods: Current literature on AEDs was reviewed in MedLine and EBSCO databases using the following keywords: "atypical eating disorders", "eating disorders not otherwise specified", "EDNOS", "diagnosis", "treatment", and "prevalence". All articles published between 1980 and 2010 were considered. Results: There is currently no consensus regarding the definition of AEDs. Current proposals for the classification of EDs in the upcoming fifth edition of the Diagnostic and Statistical Manual of Mental Disorders are marked by less strict criteria for typical EDs, which should lead to limiting the field of AEDs. AEDs are among the most prevalent EDs in the general population and clinical setting. AEDs affect primarily adolescents and young adult women, causing an important psychological, somatic, and social burden. The incidence of AEDs is much higher than that reported for typical EDs. AEDs are frequently underdiagnosed because of limitations in patient disclosure and the lack of specific clinical symptoms. AED remission occurs in 75% of cases, and transition to typical EDs may also occur; nevertheless, the transition from a typical ED to an AED seems to be associated with a good prognosis. Conclusion: As described in this review, AEDs are more typical and severe than was generally thought. Treatment should therefore be started as soon as possible. AEDs may be a transitional form of typical ED that could be more sensitive to prevention strategies.