Latent structure of eating disorder symptoms: a factor analytic and taxometric investigation.

OBJECTIVE: The latent structure of eating disorder symptoms, as defined by DSM-IV, was tested in a group of 341 women with and without an eating disorder diagnosis.
METHOD: The study group consisted of 201 participants with a diagnosis of anorexia nervosa, bulimia nervosa, binge eating disorder, or eating disorder not otherwise specified; 24 comparison subjects who were obese but did not have an eating disorder diagnosis; and 116 normal-weight comparison subjects. The presence and severity of DSM-IV eating disorder symptoms was assessed with the semi-structured Interview for the Diagnosis of Eating Disorders-IV. The study group was randomly divided into two subgroups for factor analytic studies, and the data were subjected to exploratory and confirmatory factor analysis. Pilot taxometric analyses were used to examine whether the obtained factors represented true dimensions or latent discrete classes.
RESULTS: In exploratory factor analyses with data from subgroup 1, three factors were found to account for 66% of the variance in eating disorder symptoms: binge eating, fear of fatness/compensatory behaviors, and drive for extreme thinness. Confirmatory factor analysis cross-validated this factor structure with data from subgroup 2. The eating disorder groups and comparison groups were found to differ on at least one of the three factors. The results of the taxometric analyses were inconsistent with a strictly dimensional model of eating disorders and suggested that some features may be dimensional whereas others may be taxonic (discrete). DISCUSSION: The eating disorders, as defined by DSM-IV, can be conceptualized as having three latent features. Taxometric tests found empirical support for conceptualizing bulimia nervosa and binge eating disorder as discrete syndromes.