Atypical anorexia nervosa: A scoping review to determine priorities in research and clinical practice

BackgroundThere is currently a limited understanding of the identification, nature, and treatment of Atypical Anorexia Nervosa (AAN). Recent systematic reviews have identified only small numbers of candidate papers, and some areas lack any meaningful review so far - particularly treatment outcomes. A key issue is the lack of clarity in the literature regarding the definition of weight loss criteria.ObjectivesThis scoping review aimed to determine the nature and extent of our knowledge of AAN, in order to assist in the development of future systematic reviews and meta-analyses, as well as indicating what further research is needed.MethodFollowing the identification of 6747 records, 317 records using the term AAN or a defined equivalent were identified from six databases, including the 'grey' literature.ResultsOf the 317 studies, 111 provided participant characteristics, and only 10 provided discrete treatment outcomes. Each of these subsets of the data are tabulated and supported with supplementary material, so that future systematic reviewers can access this resource.DiscussionThe pattern and content of the existing studies allows recommendations to be made regarding future reviews, research and clinical practice. There is a particular need for clear weight/weight loss criteria and adequate interventions. Our identification of Atypical Anorexia Nervosa (AAN) and associated interventions lacks the evidence-based clarity that can be provided by effective reviews of the field. Relatively few studies provide discrete characteristics or treatment outcomes of AAN. Guidance is outlined regarding reporting criteria for such studies for authors and journals.