Eating Disorders

1
Eating Disorders

• Biomedical explanation
• Inherited behavioural traits
• Neurochemical abnormalities in brain systems
  associated with appetite eating
• Structural damage to brain areas associated with
  eating

psychlotron.org.uk
2
Biomedical Hypotheses

• Genetics
• EDs should run in families
• Degree of relatedness to ED patient should
  influence risk of developing EDs in others
• Neurochemistry
• Should be detectable abnormalities in
  neurotransmitters/hormones
• EDs should respond to drug treatment

psychlotron.org.uk
3
Genetics

• EDs tend to run in families
• 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

psychlotron.org.uk
4
Genetics

• Holland et al (1984) concordance rates for
  anorexia
• 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)

psychlotron.org.uk
5
Brain Neurochemistry

• No evidence for structural damage to
  appetite-related hypothamalic regions
• Some evidence for chemical abnormalities
• Amenorrhoea may precede onset of ED symptoms
• BN may respond to drug treatment (serotoninergic
  antidepressants)
• Difficulty telling cause from effect

psychlotron.org.uk