GENETIC

• WHAT IS THE GENETIC EXPLANATION OF ANOREXIA NERVOSA?

  Guisinger's 'adapted to flee famine' hypothesis
• KEY POINTS OF THE GENETIC EXPLANATION OF ANOREXIA NERVOSA?

  RESTRICTING FOOD INTAKE

  • necessary when little food to share

  DENIAL OF STARVATION

  • defence mechanism

  HYPERACTIVITY

  • motivated to migrate and flee
• KEY POINTS OF GUISINGER'S THEORY?

  • loss of excess weight causes symptoms
  • those who are genetically susceptible and lose too much weight trigger adaptions
• EVALUATION OF GENETIC EXPLANATION OF ANOREXIA NERVOSA?

  + explains anorexia in men, other animals and other times

  -expect more instances in males

  -doesn't explain why patients refuse to eat when food is available

  + Holland

  + Holland and Treasure

  -no specific gene
• HOLLAND?

  56% concordance rates for AN in monozygotic twins, 5% dizygotic twins
• HOLLAND AND TREASURE?

  • 65% concordance rates in AN in monozygotic twins
  • 32% dizygotic twins
  • high heritability
  • only 65% so other factors affecting (e.g. family dynamic, cognitive vulnerability, media role models)
  • validity depends on extent of shared environment