Abnormality The Biological Approach

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Abnormality The Biological Approach

• By Andrew and Hannah

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Infection

• Park studied 4 anorexic people.
• Each of these people had glandular fever or a
  similar disease before the start of their eating
  disorder.
• Disease screwed up the brain (hypothalamus) which
  caused the eating disorder.
• Physical disease

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Genetic Factors

• Members of the same family are more likely (4/5
  times more likely) to have eating disorders.

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Twin Studies

• Monozygotic Twins share exactly the same genes
• Dizygotic (non identical twins) same genetic
  relatedness as any siblings .
• Only difference is their genetic similarities.
• If an eating disorder is inherited we would
  expect to find more causes of MZ twins both
  having the disorder than DZ twins.

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Twin Studies Continued

• Concordance rates means to the extent to which a
  certain trait in both twins is in concord or
  agreement.
• Holland Anorexia
• Monozygotic was 56
• Dizygotic was 5
• Kendler Bulimia
• Monozygotic was 23
• Dizygotic was 9
• These studies provide strong support for the
  genetic hypothesis

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Evaluation Of Genetic Factors

• Finding suggest that genetic factors play a part
  in eating disorders especially anorexia nervosa.
• Other factors are important as well as inherited
  genes.
• Secondly another argument against the genetic
  explanation taken on its own refers to the recent
  dramatic increase in the number of people
  suffering from eating disorders.

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Biochemical Factors

• Serotonin is a neurotransmitter which affects
  arousal and sleep.
• Fava et al. link between anorexia and levels of
  serotonin and noradrenalin.
• Carbohydrates increase serotonin in the brain.

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Evaluation Of Biochemical

• Bumlics do not focus on starchy foods, such as
  carbohydrates, when they binge
• Biochemical imbalances in anorexics not cause but
  an effect
• Lack of mestruation in anorexics is probably
  caused by the disorder.

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Neuro-Anatomy

• Suggested that anorexics have brain
  abnormalities. Sections of the hypothalamus
  controls things such as eating and menstruation.
• The rentromedial hypothalamus suppressed hunger
• The lateral hypothalamus stimulates feelings.
• Therefore, is likely that anorexics have
  disturbed hypothalamic functioning

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Evaluation of Neuro-anatomy

• Altered hypothalamic activity may well not be a
  cause of anorexia
• Post-mortoms have not revealed any lesions in
  this area of the brain