This essay will be investigating the eating disorder Bulimia nervosa.

b)         Concerning the etiology of Bulimia it it obvious that Bulimia isn’t the result of a single factor. Much rather bulimia seems to be caused by an interaction of biological, sociocultural and cognitive factors. The extent to which each of the elements contributes to the disorder is debatable and will be investigated in this essay.

There are two biological factors which could contribute to bulimia, these are genetics and the neurotransmitter serotonin. The ingestion of carbohydrate rich meals triggers the synthesis of serotonin, this signal will reduce the likelihood that a person will eat carbohydrate rich foods in their next meal. One theory concerning bulimia nervosa is that it is the behavioural manifestation of under activity of serotonin. This is supported by a study by H.E. Gwirtsman who injected rats with drugs that enhance serotonin-energetic transmission and found that they affect the amount of dietary carbohydrates and proteins that are consumed by the rats. Therefore the constantly low manifested serotonin levels could be an explanation for the binge eating.

Another biological factor which can influence bulimia is the genetic make up of a person. Certain genetics could increase the chances of a person getting bulimia. This is shown in a study by Kendler et al. in 1991, who focused on bulimia in female twins. They investigated the concordance for bulimia nervosa in monozygotic and dizygotic twins. The study used 2163 female twins of which at least one had bulimia. The results were that the concordance rate for MZ twins was 23% while for DZ twins it was only 9%. This study shows that there is a certain correlation between genetics and bulimia as the concordance was far higher in MZ twins. However it also clarifies that bulimia is definitely not purely due to genetics as the concordance rate was far below 100%.

Sociocultural factors can also influence the development of bulimia in a patient. Especially in Western societies, outward appearance is of high importance and women see other women as awarded for looking slim and often envy the attention and admiration they get. According to Cooper (1994), the “Social Identity Theory” will lead many women to imitate this rewarded behaviour and strive to be slim, which is vicarious reinforcement. The effect of society on the development of bulimia can also be seen in a study by Nasser in 1986. Nasser compared Egyptian women studying in Cairo and in London. He found that none of the women in Cairo developed an eating disorder, while of the women studying in London, 12% developed one. This study demonstrates that again cultural influence isn’t the primary factor as otherwise all women studying in London would have developed an eating disorder, however it does show that the cultural factor contributes to the development of bulimia. This is also suggested in a study by Lee, Hsu and Wing in 1992, who investigated Chinese and American women. They found that in the US, women have an intense fear of becoming fat, while in China slimness is associated with ill-health. They noted that in China obesity is seen as a sign of health, wealth and prosperity and that bulimia was nearly none-existent. Cultural setting plays a large role in the development of bulimia. In the study women were far more likely to develop the disorder bulimia when there is the social pressure of being thin, compared to when there isn’t.

 This pressure is especially strong for women and this could be an indication for why the prevalence of bulimia is higher in women. Fallon and Rozin in 1998, found that when families were asked to compare their body shape to their ideal body, only the sons reported their body shape as acceptable, while especially mother and daughter wanted to be thinner. The pressure society puts on women probably has an effect on the development of bulimia.

Similar to anorexia nervosa, bulimia nervosa can also be influenced by the cognitive factor of self-perception. Generally people who develop bulimia are not overweight but suffer from a distorted perception of their body image. The correlation between the body image people have of themselves and bulimia prevalence is shown in a study by Jaeger et al. from 2002. They sampled 1751 medical and nursing students from 12 countries, including a mixture of Western and non-Western ones. A self-report method was used to obtain data on body dissatisfaction, self-esteem and dieting behaviour. The result was that extreme body dissatisfaction was found in mediterranean countries, followed by northern European countries, countries in the process of modernisation and then non-Western countries had the lowest levels of body dissatisfaction. As this is also very similar to the order of the greatest prevalence of bulimia it implies that there is a correlation between self-perception and bulimia.

Overall all the above factors can be seen as part of the etiology of bulimia, however none can be viewed as singularly causing bulimia, as neither in genetics nor anywhere else was there a rate of 100% of people developing bulimia when a certain factor was given. Therefore all factors contribute and the development of bulimia comes from an interaction between them.