The exact etiology of bulimia nervosa is not clear.
At present, most scholars tend to speculate on the cause from biogenetic and psychosocial factors. On the biogenetic side, the incidence of drug dependence, affective disorders and simple obesity is higher among family members of bulimia nervosa patients; on the psychosocial side, low self-esteem and perfectionists are the high-risk group for the disease, who are so dissatisfied with their physical appearance or weight that they first resort to strict dieting measures and then, with a vengeance, overeat to vent.