On the Continuum of Eating Disorders

Theorists and researchers have long debated as to whether the differences between subthreshold levels of eating disturbances and diagnosable eating disorders are a difference of degree (the continuum hypothesis) or a difference of kind (the discontinuity hypothesis). The present study investigated the relationship between level of eating disordered behaviour and the psychopathology associated with, and thought by some to be prodromal factors in, the development of clinically diagnosable eating disorders. Adolescent female students from both public and private schools, and adolescent female patients in treatment for subclinical or full syndrome anorexia or bulimia nervosa, were classified into five groups (asymptomatic, normal, symptomatic, subclinical, and eating disordered) on the basis of their responses to a questionnaire which provides a measure of current weight-control practices and yields a DSM-IV eating disorder diagnosis. Eating disorder symptomatology and related psychopathology were assessed by the Eating Disorder Inventory-2. A discriminant function analysis was performed to determine the number and nature of the dimensions required to distinguish among the five groups. Two functions were significant. The first function, thinness strivings, distinguishes among the normal, symptomatic, and subclinical groups; the asymptomatic group was equivalent to the normal group, and the eating disordered group was equivalent to the subclinical group. The second function, body dissatisfaction/psychopathology, distinguishes the eating disordered group from the subclinical group, and the asymptomatic group from the normal group. Results are discussed as being consistent with a view of eating disorders as being distinct from below-threshold levels of eating disturbances, and implications for assessment and treatment are discussed.