Etiological Relationships Between Eating Disorder Symptoms and Dimensions of Personality Disorder

A preliminary exploration of the etiological factors that may contribute to the relationship between eating disorder symptoms and personality disorder traits is reported based on a general-population twin sample of 221 pairs. Symptoms of eating disorder, assessed using the Health Information Questionnaire (HIQ), formed 3 factors: Concern for Overeating, Purging, and Body Mass Index (BMI). Modest genetic influences were observed on Concern for Overeating, possible non-additive genetic effects on Purging, and substantial additive genetic effects for BMI. Substantial nonshared environmental effects occurred with the Concern with Overeating and Purging scales, and common environmental effects were noted for the Concern with Overeating scale. Personality disorder traits were assessed using the Dimensional Assessment of Personality Pathology-Basic Questionnaire (DAPP-BQ). Phenotypic, genetic, and environmental correlations between the HIQ scales and higher-order personality disorder factors were modest. The strongest relationship was between Concern with Overeating and Emotional Dysregulation. Relationships among DAPP-BQ basic trait scales and eating disorder symptoms were modest and relatively non-specific. The strongest relationships were with the Concern with Overeating scale. Purging also showed a modest relationship with affective lability and self-harm.