Background. Although cases of early onset anorexia nervosa have been described, there has been no systematic comparison of early onset cases with classic cases of later onset, or with other forms of early onset eating disturbance.

Method. A consecutive series of patients referred to two specialist child and adolescent eating disorder services with a clinical diagnosis of eating disorder (N = 126) was systematically assessed using a child version of the Eating Disorder Examination (EDE) and the K-SADS interview.

Results. Of 86 patients with a diagnosis of eating disorder of early onset, 38 received a clinical diagnosis of anorexia nervosa (AN). The remainder were mainly diagnosed as having food avoidance emotional disorder (25 patients) and selective eating (17 patients). Six received other diagnoses (bulimia nervosa, or functional dysphasia). These 48 patients were combined to form a group of early onset non-AN eating disturbance. In terms of specific eating disorder psychopathology and general psychopathology, the early onset AN group was very similar to the late onset AN sample. When the two early onset groups were compared, there was a marked difference between them in terms of eating disorder psychopathology. A discriminant function analysis using the EDE information produced a clear discrimination, with the EDE restraint and shape concern subscales doing most of the discrimination work.

Conclusions. The specific psychopathology of AN of early onset is very similar to that of classic adolescent onset AN. Other forms of early onset eating disorder do not evidence this specific psychopathology.