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.
Clinical Implications· New treatments for AN that are specifically tailored to address risk factors (causal or maintaining) may improve the outcome of AN. · Cognitive remediation addressing how AN sufferers think (for example, the superiority of detail over global processing and the difficulty in changing set) rather than thought content could be used to change compulsive elements of the psychopathology. · The vulnerability and plasticity of the reward and motivation pathways in adolescence may explain how a failure of treatment early in the course of the illness may lead to a poor outcome.
Limitations· This is not a systematic review of risk factors for AN. · Little to no research exists examining how genetic factors moderate or mediate some of the biological aspects of AN. · Some aspects of the eating disorder phenotype are moderated by environmental factors, and research designs that examine interactions between fixed and fluid aspects of the psychopathology are needed.