Morbidity risk for obsessive-compulsive spectrum disorders in first-degreerelatives of patients with eating disorders

Objective: A hypothesis that eating disorders are a phenomenological varian t of obsessive-compulsive disorder (OCD) has been proposed. This study was conducted to determine whether anorexia nervosa and bulimia, the two main e ating disorders, are familial and whether the risk for obsessive-compulsive spectrum disorders (OCD and tic disorders) is higher in families of patien ts with eating disorders. Method: The morbidity risk for obsessive-compulsive spectrum disorders in f irst-degree relatives of 136 female probands with eating disorders (84 with anorexia nervosa, 52 with bulimia) was compared to that for first-degree r elatives of 72 female comparison subjects. Results: The morbidity risk for obsessive-compulsive spectrum disorders was significantly higher among the 436 relatives of the eating disorder proban ds than among the 358 relatives of the comparison subjects (9.69% versus 0% ). This finding was independent of any comorbid diagnosis of an obsessive-c ompulsive spectrum disorder in the eating disorder probands. The eating dis order group and the comparison group did not differ in familial risk for ea ting disorders and tic disorders. Conclusions: To better understand the genetic components of eating disorder s, these disorders should be considered as part of the obsessive-compulsive spectrum of disorders.