Schizophrenia : drug therapy

Question 1

what is a typical anti-psychotic?

Answer 1

they bind to the dopamine receptors but don’t stimulate them, reducing the action of dopamine. initially dopamine levels build up but then production is reduced. This normalises neurotransmission in key areas of the brain, by reducing stimulation of the dopamine system reducing positive symptoms such as hallucinations.

Question 2

what are atypical anti-psychotics?

Answer 2

they block dopamine receptors like typical anti-psychotics. However, they only temporarily occupy the receptors and then rapidly dissociate to allow normal dopamine transmission. This is thought to be responsible for fewer side effects. They also act on other neurotransmitters, particularly serotonin and they address negative symptoms e.g. avolition as well as positive symptoms.

Question 3

what are examples of typical anti-psychotics?

Answer 3

chlorpromazine (dopamine antagonists)

Question 4

what are examples of atypical anti-psychotics?

Answer 4

clozapine and risperidone

Question 5

what are dopamine antagonists?

Answer 5

these are also known as typical anti-psychotics, they bind to D2 receptors but they don’t stimulate them, they just block the action of dopamine.

Question 6

kapur et al 2000 dopamine antagonists

Answer 6

in order for dopamine antagonists to work 60% - 75% of mesolimbic pathway D2 receptors must be blocked. These drugs don’t only work in that pathway, so there are some pretty horrible side effects.

Question 7

what happens when someone takes an atypical antipsychotic?

Answer 7

these act on D2 receptors as wellso they help with positive symptoms, Side effects are less severe too, since the blockage doesn’t last as long (rapid dissociation).They also act on serotonin.

Question 8

what other effects do atypical antipsychotics?

Answer 8

atypical drugs will not only reduce SZ symptoms but they also reduce deppresion and anxiety which is great because 30-50% of SZ patients attempt suicide at some point

Question 9

what are the similarity between typical/atypical drugs?

Answer 9

Lowers the amount of dopamine.
Bad side effects such as tardive dyskinesia.
Based on assumptions from Biological approach.

Question 10

what is tardive dyskenesia

Answer 10

condition where your face, body or both make sudden, irregular movements which you cannot control.

Question 11

what is the difference between atypical and typical drugs

Answer 11

typical
- only affects dopamine
- has little affect on neg symp
- has more side effects because of their mechanism of action, sleep and digestive issues
atypical
- also affects seratonin
- works to alliveate +/- symp
- has fewer side effects