Over the years there has always been lots of debate over peoples figures and inevitably the eating disorders that follow from people trying to change their bodies into something more ‘preferable’, or at least different to what they are at the moment. The biological model explains how onset and/or development of eating disorders are due to genetic factors or to some biological abnormality or malfunction, which may be genetically based.
There are four parts to this model Neuroanatomy First off is Neuroanatomy; this theory is based on the belief that there is an error in the hypothalamus, which stops it from working properly. The function of the hypothalamus (a part of the brain) is to keep all the bodies functions in equilibrium, if it isn’t working right an eating disorder can be the result.
Cnattingius et al researched this by studying hospital records of about 4000 female babies born in Sweden between 1973 and 1984. From this he found that 781 of them were later hospitalised due to anorexia. 5 of these females that became anorexic had experienced trauma as a baby therefore showing a connection where brain damage caused by this trauma, could increase the risk of anorexia.
Lambe et al found that people with anorexia whose weight returned to normal had reduced grey matter in their brain. This could suggest that anorexia could be caused by brain damage, or the anorexia could have changed the structure of the brain. There are very few researches backing up the theory of Neuroanatomy (brain damage) could be the cause of eating disorders. The main study was that of Cnattingius and this was very small scale with negligible results – only 5 out of 781 of the anorexics had brain damage from trauma at birth.
Also the research conducted by Lambe et al was inconclusive as to whether the changed structure of the brain was due to the anorexia or was the cause of it. Genetic Evidence has been found that suggests that female relatives of young women with eating disorders are between 5 and 10 times more likely than the general population to develop eating disorders themselves. Strober and Humphrey found evidence supporting this theory, however it is hard to tell if the anorexia was caused by genetics or if it was related to the environment the girls/women were living in. For instance, if a girl is living with someone with anorexic eating habits, they would pick some up and possibly emulate (copy) them.
Twin studies by Holland et al found more evidence to support this. They studied 30 pairs of female twins, with at least on of the twins suffered from anorexia. They found that if an identical or monozygotic twin suffered from anorexia, there was 55% more chance that the other twin would also suffer from the disorder. As mentioned above, it is hard to decipher if the eating disorder is actually due to the genes of the person, or if it is due to environment, or even both.
Biochemical Another theory about the cause of eating disorders is that chemical imbalances in the body would change eating patterns and appetites, thus causing the person to have an eating disorder. Collier et al said that when the body responds to stress, adrenaline and cortisol are produced and the affect from this is a loss of appetite (symptom of the sympathetic branch being activated.) When stress levels decrease, the appetite should return to normal, however they lack the hormone which brings the appetite back (AVP)
Fichier and Pirke starved normal individuals, which caused changes in neurotransmitters and hormone levels. Therefore this shows that they are a consequence not a cause from this disorder. The starvation hypothesis researched by Fichier and Pirke suggested that neurotransmitter and hormone disorders are a consequence rather than a cause of emotional distress, thus giving negligible evidence on the theory that the change in hormone levels were the cause rather than a consequence of the eating disorder.
Infection
The last theory to do with eating disorders and the medical model is that infection could be the cause of it. Research was done finding connections between the studies having an infection and then suffering from an eating disorder, or it worsening. Park et al- found that glandular fever sometimes occurs prior to the onset of anorexia. Glandular fever may upset the functioning of the hypothalamus.
Child and adolescent psychiatrist Dr Mae S. Sokol of Menninger Clinic in Topeka Kansas reported that three adolescents he was treating with anorexia nervosa, suddenly started or worsened at around the same time as they were suffering from streptococcal or other infection.. in one case the teenage boy developed anorexia after a bad case of strep thoat. His eating disorder decreased while he was taking antibiotics prescribed for a sinus infection. When the antibiotics were finished, the anorexia returned. The patient was put back on antibiotics, and he improved again. Reports by Dr John F and other psychiatrists suggested a similar mechanism in certain cases of anorexia nervosa, which backed up the research by Dr Mae S. Sokol.