Biological explanation of Anorexia: Neurotransmitters

Question 1

Serotonin

Answer 1

• Stabilizes our mood, feeling of well being and happiness
• Also helps with sleep and digestion

Question 2

Serotonin effects of Anorexia

Answer 2

• Abnormally high levels of serotonin –> high levels of anxiety –> heightened levels of anxiety can lead to fear of gaining weight –> binging/purging behaviour in people with anorexia
• Abnormally high levels of serotonin –> Ventromedial hypothalamus is stimulate
  –> makes the person feel full, so they don’t eat
• Abnormally eating behaviour in people with anorexia –> them not eating food –> no tryptophan which comes from food, which is the chemical needed to make serotonin –> without food serotonin cannot be produced in the brain –> lowered level of serotonin in the body –> reduces levels of anxiety

Question 3

Evidence for Serotonin effects

Answer 3

• Bailer et al:
  Patients who were in remission from anorexia showed increased amount of serotonin in their brain, this related to the measure of anxiety in women, these women had high levels of anxiety also had high levels of serotonin a year after remission. Suggesting that serotonin levels increasing is linked to increased anxiety
• Kaye and Frank:
  PET scans showed that recovered former patients have elevated serotonin levels

Question 4

Dopamine

Answer 4

• Involved in emotion, cognition and also reinforcement
• It is released when ‘good things’ happen so you continue the behaviour

Question 5

Basal Ganglia

Answer 5

• Associated with learning from experiences based on rewards

Question 6

Dopamine effects on Anorexia

Answer 6

• Abnormally high levels of dopamine in the basal ganglia –> Interferes with ability to seek or respond to pleasurable activities –> Changing the way the person interprets rewards –> The reward of eating food is disrupted with an overactive basal ganglia –> Instead food leads to anxiety –> Person not wanting to eat food

Question 7

Evidence for Dopamine effects

Answer 7

• Kaye et al:
  Used a PET scan to compared dopamine activity in the brains of 10 women recovering from AN and 12 healthy controls. AN women had an overactivity in dopamine receptors of the basal ganglia. Therefore showing there is an overactivity causing individuals with AN to have difficulties associated good feeling with pleasurable activities such as food
• Kaye:
  Women with AN increased levels of dopamine had increase anxiety, however the controls who were normal had an increase dopamine-induced feelings of pleasure

Question 8

Weakness of Biological Explanation for Anorexia

Answer 8

• It is too reductionist, only considering neurotransmitters as a cause and as such drugs developed can treat those causes
• Drugs used to treat other disordered linked to level of serotonin and dopamine, SSRI’s and anti psychotics are not very effective to treat anorexia
• Suggesting the disorder is not purely related to levels of dopamine and serotonin, and other factors may be involved such as lifetime experiences