Answer to Question 1
Fairburn conceptualizes the cause of Bulimia nervosa as a combination of maladaptive tendencies, including an excessive emphasis on weight and shape, perfectionism, and dichotomous black or white thinking. His program, that we will replicate, involves three stages. The first stage involves education and behavioral strategies to normalize eating patterns and end the cycle of eating restraint followed by binging and purging. Second, we will introduce traditional cognitive therapy methods that aim to convince the client of her cognitive errors, such as illogical and dysfunctional beliefs about the importance of weight and its the connection to self-image. This stage will draw heavily on the methods introduced by Beck. Third, as clients develop more logical and reasonable cognitions and beliefs, we will attempt to consolidate these into day to day realistic expectations about weight, diet and strategies for relapse prevention.
Answer to Question 2
Concordance rates for bulimia are higher for monozygotic twins than for dizygotic twins. However, the difference can be explained by several different heritable mechanisms. Eating disorders are unlikely to be directly inherited. Genetics may influence personality characteristic that lead to bulimia, or a certain body type or weight set point may be inherited. Genes clearly affect weight and body type, but we cannot mindlessly conclude that eating disorders are genetic without carefully considering genetic mechanisms and gene-environment interactions. In rare instances, a hormonal disturbance or a lesion in the hypothalamus has been linked to eating disorders.