The relation between risk factors for binge eating and bulimia nervosa: a population-based female twin study.

This study investigated the differential risk factors for the initiation of binge eating and the transition from binge eating to bulimia nervosa. Women from a population-based twin registry (850 complete pairs) were assessed with respect to specific measured variables (including demographics, religiosity, lifetime psychopathology, current symptomatology, and personality) and latent genetic and environmental variables. Because of the relative rarity of bulimia nervosa, statistical power was low, but findings suggested considerable overlap between the genetic risk factors for the development of binge eating and the genetic risk factors for the transition from binge eating to bulimia nervosa. Genetic risk factors for binge eating and bulimia nervosa may be largely similar, whereas nonshared environment may be important in influencing the risk for bulimia nervosa once binge eating is initiated.