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Eating Disorders
Biomedical explanation
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Inherited behavioural traits
Neurochemical abnormalities in brain systems
associated with appetite & eating
Structural damage to brain areas associated
with eating
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Biomedical Hypotheses
Genetics
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EDs should run in families
Degree of relatedness to ED patient should
influence risk of developing EDs in others
Neurochemistry
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Should be detectable abnormalities in
neurotransmitters/hormones
EDs should respond to drug treatment
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Genetics
EDs tend to run in families
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Kaye (1999) - 10% of ED patients have a
relative who is also an ED patient
Depression, anxiety, OCD more prevalent in
families of ED patients
Difficult to separate effects of genes from
effects of shared environment
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Genetics
Holland et al (1984); concordance rates for
anorexia:
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55% MZ twins
7% DZ twins
Reduces confounding effect of shared
environment
Suggests genetic contribution but not cause
Small sample; finding not always replicated (e.g.
Wade et al, 1998)
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Brain & Neurochemistry
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No evidence for structural damage to
appetite-related hypothamalic regions
Some evidence for chemical abnormalities
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Amenorrhoea may precede onset of ED
symptoms
BN may respond to drug treatment
(serotoninergic antidepressants)
Difficulty telling cause from effect
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