schizophrenia- biological treatments

Question 1

typical antipsychotics:

Answer 1

dopamine antagonists
-been around since 1950s
-act as antagonists in the dopamine system and aim to reduce that action of dopamine
-strongly associated w dopamine hypothesis

Question 2

how do antipsychotics work?

Answer 2

-block dopamine receptors in synapses in the brain
-reducing the action of dopamine
-initially the levels build up after taking chlorpromazine but then production is reduced
-this normalises neurotransmission in key areas of brain, which reduces symptoms like hallucinations

Question 3

what is an example of a typical antipsychotic?

Answer 3

chlorpromazine

Question 4

what is the other effect of chloromazopine?

Answer 4

-sedation
-has an effect on histamine receptors which appears to lead to a sedation effect
-also used generally to calm anxious patients when first admitted to hospital

Question 5

what’s was the aim of atypical antipsychotics?

Answer 5

-newer drugs
-maintain and improve upon the effectiveness of drugs in suppressing the symptoms of psychosis
-also minimise the side effects of the drugs used

Question 6

what is an example of an atypical antipsychotic?

Answer 6

clozapine

Question 7

how do atypical antipsychotics (clozapine) work?

Answer 7

-c binds to dopamine receptors as chlorpromazine does but also acts on serotonin and glutamate receptors
-this drug was more effective than typical antipsychotics- clozapine reduces depression and anxiety as well as improving cognitive functioning
-also improves mood, important as up to 50% of people w sz attempt suicide

Question 8

how does risperidone work?

Answer 8

-binds to dopamine and serotonin receptors
-but binds more strongly to dopamine and so is more effective in smaller doses than most antipsychotics and has fewer side effects

Question 9

what was developed after clozapine and why?

Answer 9

Risperidone
-developed in the 1990s
-clozapine involved in the deaths of some people from agranulocytosis (blood condition)

Question 10

ao3 of biological therapy for sz: evidence of effectiveness

Answer 10

-thorney et al. (2003) reviewed data from 13 trials (1221 p’s) found chlorpromazine was associated w better functioning and reduced symptom severity compared w placebo
-also support for benefits of atypical antipsychs. Meltzer (2012) concluded clozapine is more effective than typical antipsychs, and that it is effective in 30-50% of treatment-resistant cases
-as far as we can tell antipsychs work

Question 11

ao3 of biological therapy for sz: likelihood of side effects

Answer 11

typical are associated w dizziness, agitation, sleepiness, weight-gain, etc. L/T use can lead to lip-smaking and grimacing due to dopamine sensitivity (tardive dyskinesia)
-most serious side effect is neuroleptic malignant syndrome (NMS) caused by blocking dopamine action in hypothalamus (can be fatal, disrupted regulation of several body systems)
-means antipsychotics can do harm as well as good and individuals may avoid them (reducing effectiveness)

Question 12

ao3 of biological therapy for sz: we don’t know why they work

Answer 12

-use of most is strongly tied up w dopamine hypothesis and idea that there are higher-than-usual levels of dopamine in the subcortex of people w/sz
-but evidence this may not be correct and dopamine levels in brain too low rather than too high. if so, antipsychs shouldn’t work
-may not be best treatment to opt for- perhaps some other factor involved in their apparent success