Causes of Eating Disorders (anorexia and Bulimia Nervosa)

Eating disorders are devastating psychological illnesses caused by a variety of factors including family pressure, biochemical factors, possible genetic susceptibility and cultural influences. In the following short essay I will be discussing the possible causes and treatments available according to different psychological models regarding eating disorders.

Anorexia is defined as an eating disorder characterized by an overwhelming, irrational fear of being fat, compulsive dieting to the point of self starvation and excessive weight loss. In which the sufferer is 80% below the expected average body weight. However bulimic's strive to satisfy a constant craving for food and nearly all patients are within 10% of their normal weight. This eating disorder involves bingeing and purging more than twice a week, which can have serious medical consequences. Most patients suffering from bulimia are in their twenties and are somewhat older than sufferers from anorexia. Bulimia nervosa resembles anorexia in that both disorders are far more common in western societies and occur more often in middle class than working class families.

The medical model considers the possibility of infection, biochemical imbalances and neuroanotmomy dysfunctions as the prime cause of the above eating disorders. They believe that somatic illnesses may act as a contributing factor in bulimia and anorexia nervosa. Park et al studied four women in 1995 all of whom had had glandular fever before the onset of the eating disorder. He argues that the glandular fever may have influenced the functioning of the hypothalamus, resulting in changes in the body's chemical balance.

Holland et al suggested that genetic factors play an important role in the development of eating disorders. In his twin study theory, he studied monozygotic and dizygotic twins suffering from anorexia nervosa. The monozygotic twins are genetically identical whereas the dizygotic twins have the same genes as any siblings. The twins under normal circumstances will share the same environment, for example the same womb, and will also share similar experiences. The only difference between the twins is their genetic similarity. Therefore, if an eating disorder is inherited according to Holland et al then we would expect to find more cases of monozygotic twins both having the disorder than dizygotic twins. He discovered that the concordance rate (certain traits identical in both twins) for monozygotic twins was 56% compared to 5% for dizygotic twins. This study and many other twin studies provide strong evidence that genes play a key role in the inheritance of eating disorders.

Serotonin a chemical neurotransmitter may be involved in some cases of eating disorders, because there has been reported links between anorexic behaviour and changes in the levels of serotonin. Low level's of serotonin cause aggressiveness, lack of sleep and stress. Nevertheless this can be overcome by eating large amounts of food containing carbohydrates or antidepressants (selective serotonin reuptake). It has also been argued that amenorrhoea a classic symptom of anorexia nervosa is due to an underlying problem with the endocrine system. The endocrine system is responsible for the production of the hormones that control the menstrual cycle.

Individuals with eating disorders may have brain abnormalities according to some psychologists which causes an onset of the eating disorder. Part of the brain controlling eating, menstruation and sexual activity which is known as the hypothalamus may be operating inadequately.

There have been a variety of psychodynamic explanations concerning eating disorders. One possibility being, eating disorders act as a means of avoiding sexual maturity. Minuchin's family systems theory suggests that anorexia develops as a result of enmeshed family dynamics. This means that none of the family members have a clear identity and thus impose great pressures on children denying them of any independence. According to various psychodynamic theories adolescence is the fifth phase of psychosexual development and is crucial for self independence. This will result in family conflicts and therefore the child will rebel against its constraints by refusing to eat. However, Hilda Burch studies 64 anorexic patients and suggested anorexia is related to mother-daughter conflicts over identity and autonomy. Burch discovered that mother's did not attend to the child need ie the baby was feed when the mother felt hungry. Food was also used as a means of comfort, consequently if the child was unhappy food was offered as compensation.

The fact that anorexia specifically emerges in adolescence lead some psychodynamic theorists to believe anorexia is related to the onset of sexual fears .i.e. becoming