Getting beneath the phenotype of anorexia nervosa: the search for viable endophenotypes and genotypes.

Treatment for anorexia nervosa has changed little from that described by Gull over a century ago. To focus merely on symptomatic relief from "not eating," as occurs with some forms of hospital care, is primitive. The evidence base to guide treatment is thin. Nevertheless, there is hope that better understanding of the causes and maintaining factors may translate into more sophisticated treatments. This review aims to look beyond the overt and startling "not eating" phenotype of anorexia nervosa and consider eating disorder endophenotypes. The first part of the review sets the eating behaviour, clinical, and psychopathological features into the context of what is now understood about the central control of appetite. The evidence base for a framework of potential eating disorder endophenotypes follows. Finally, ideas about how to translate endophenotypes into treatment are introduced.