Biological Explanations for Anorexia Nervosa Psychology

2938 Words Dec 26th, 2012 12 Pages
Biological explanations for anorexia nervosa
Biological explanations for anorexia nervosa include neural explanations and evolutionary explanations.
1st BIOLOGICAL EXPLANATION - Neurotransmitters
-Serotonin
Disturbances in the levels of the neurotransmitter serotonin appear to be a characteristic of individuals with eating disorders. Kaye 2005 found a reduction in the levels of the serotonin metabolite 5-HIAA in people with eating disorders. This suggests that brain serotonin pathways are underactive. Using PET scans it has been shown that there are fewer serotonin receptors in the brains of those with eating disorders. The brain serotonin system has been implicated in personality traits linked with eating disorders such as
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Birth complications may lead to brain damage cause by hypoxia (lack of oxygen). This may impair the neurodevelopment of the child. Favaro et al 2006 offers research support for birth complications being implicated in anorexia. Following a group of children from birth to adulthood, it was found that immediately before or after any obstruction of the blood supply to the placenta increased the risk of developing eating difficulties & a low birth weight.
Bulik et al 2005 suggest that mothers with anorexia expose their offspring to a ‘double disadvantage’ & that nutritional factors may be implicated if mothers have an eating disorder – the transmission of genetic vulnerability to anorexia & inadequate nutrition during pregnancy.
Research support for the role in anorexia can be offered by Mindberg and Hjem whom found that a high percentage of anorexics were born at least3 weeks premature. However not all babies that are subject to pregnancy and birth complications will then go on to have AN & such view that complications will result in AN is highly deterministic.

-Season of Birth
Research also suggest that individuals with AN are more likely to have been born during the spring months (Eagles et al 2001). Explanations for this associating include intrauterine infections during pregnancy and temperature at time of conception.
For example Willoughby et al
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