Discuss Biological Explanations of Anorexia Nervosa

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Discuss Biological explanations of Anorexia Nervosa:

There are three biological explanations of A.N; evolutionary, genetic and neurobiological. The evolutionary explanation focuses on the adapted to flee hypothesis. Guisinger (03) suggested that Anorexia served an adaptive purpose in the environment of evolutionary adaption. He explains that levels of restlessness, traits that characterise anorexia, would have been adaptive during times in which food supplies were exhausted, as hunter-gatherers had to find new sources of food. Therefore high levels of activity and denial of hunger would have promoted migration in response to famine. Alternatively, a general evolutionary explanation would suggest that the behavioural component of Anorexia Nervosa could have been adaptive, particularly in females, as the ability to refrain from eating could have promoted the survival of one’s social group during times of famine. It is assumed that people evolved from hunter/gatherer societies, in which females would be responsible for gathering; the avoidance of eating would be a useful trait for the larger group as more food would be gathered rather than consumed. This would promote survival of the collective group, which would provide more safety for its individual members and so the trait would be passed onto further generations.

The Genetic explanation of Anorexia Nervosa suggests that anorexia is genetically transmitted through generations. Based upon research into the topic it appears that individuals that have a relative with anorexia have an increased risk of developing the disorder themselves, which would suggest that anorexia is not directly inherited as many physical attributes are but that a predisposition to Anorexia is inherited. The use of twin studies allows researches to establish the relative contribution of genetics and environmental factors, as MZ twins are genetically identical while DZ twins are only genetically similar. Given the fact that both twin sets share an environment it is assumed to mean that this is controlled with any differences in proneness to Anorexia Nervosa being attributed to genetics.
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Lastly, the Neurobiological hypotheses, developed more recently suggests that abnormalities in CNS serotonin function may play a role in the development and persistence of the anorexia nervosa. Studies of long-term weight-recovered patients have revealed increased serotonin activity, such as elevated levels of serotonin metabolite 5-hydroxyindoleactic acid in the CFS and reduced binding potential of receptors, suggestive of higher levels of circulating CNS serotonin, in several brain regions (metabolites are by-products of metabolism that can be assessed infer neurotransmitter activity). Kaye et al. hypothesise that individual with anorexia nervosa may have a trait disturbance characterised by high levels of ...

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