Objective: While familial aggregation of bulimia nervosa (BN) is known to occur, the extent to which aggregation of a broader spectrum of eating disorders (ED) occurs in the families of individuals with BN is less certain.
Method: Direct interviews and blind best-estimate diagnostic procedures were used to assess lifetime histories of EDs among first-degree relatives (n = 177) of probands with BN (n = 47) and first-degree relatives (n = 190) of non-ED control probands (n = 44).
Results: Forty-three percent of sisters and 26% of mothers of BN probands had a lifetime ED diagnosis, with eating disorder not otherwise specified (ED-NOS) diagnoses being most common. These rates were significantly higher than among sisters (5%) and mothers (5%) of controls. Few male relatives of either cohort had an ED.
Conclusions: Diagnostic assessment using contemporary family-epidemiology methodology revealed very strong familial aggregation of a broad spectrum of EDs among female relatives of women with BN.