Risk factors for bulimia nervosa: a controlled study of parental psychiatric illness and divorce.

Twenty five women with normal-weight bulimia nervosa were compared with 25 age- and weight-matched women without bulimia nervosa on measures of parental psychiatric illness. Case and control probands, as well as their parents, completed the Family History Research Diagnostic Criteria (FH-RDC) interview and a battery of self-report instruments. Case probands and controls were divided into two groups based on evidence for parental psychiatric illness. The assignment of parental psychiatric illness was made by (a) a positive parental history of alcoholism or depression from the FH-RDC; or (b) evidence of parental major depression, alcoholism, or personality disorder from the self-report measures. Parental psychiatric illness occurred significantly more frequently for case probands compared to the control probands (64% vs. 24%, odds ratio = 5.6, 95% Cl = 1.7-19.2). Parental psychiatric illness was also associated with parental divorce (Fisher's exact p = .023) and a trend toward lower ratings of paternal but not maternal relationship by case probands. This study suggests parental psychiatric illness may be a risk factor for bulimia nervosa and may contribute to environmental effects through increased rates of divorce and impaired paternal relationships.