Neuroimaging and eating disorders

Eating disorders (ED) constitute a group of conditions in which abnormal eating behaviour negatively influences the psychosocial functioning of an individual. Attitudes towards food and eating and the perception of the patient’s own body are also disturbed. ED include a range of conditions, which are grouped under the diagnoses of anorexia nervosa (AN), bulimia nervosa (BN), ED not otherwise specified (EDNOS), binge eating disorder (BED) and simple obesity (OB). Within the current conceptualizations, AN and BN are classified as psychiatric diseases, whereas OB is considered to be a somatic medical condition and its inclusion into ED is controversial. The distinctions between individual diagnoses are often arbitrary, e.g. a body mass index (BMI) of 17.5 constitutes the boundary between AN and BN, the frequency of binging-purging behaviour determines the distinction between BN and EDNOS etc. To avoid confusion it is helpful to consider ED as a continuous spectrum ranging from restrictive AN to OB (Figure 6.1). The subjective importance of eating is common to all these disorders, but the drive to eat, the perception of hunger/satiety and actual body weight vary on a continuum along the spectrum.