ABSTRACT
The aim of this chapter is to summarize the biology of Eating Disorders Not Otherwise Specified. This task seems to be either impossibly difficult or facile depending on one’s mood. The task is impossible because there are very few studies that have been designed to examine this question. Most studies directly examining the biology in eating disorders choose study participants based on the clearly defined DSM-IV criteria (see APA 1994 and the Appendix). Moreover as the diagnostic criteria for Anorexia Nervosa or Bulimia Nervosa have become more or less specific, by default, the size of the group who do not exactly fulfil these diagnostic criteria, that is, eating disorder not otherwise specified, varies. Also the syndromes that lie within the current systems of clinical classification are probably biologically heterogeneous and include many phenocopies, i.e. phenotypically similar states with different underlying genotypes. The borderlines between the categories in the overeating ranges are fuzzy. The presenting symptoms in the clinic are often unreliable and seem to defy the laws of thermodynamics.
