Biological therapies

Question 1

What are drug therapies?

Answer 1

• the most common treatment for schizophrenia involves the use of antipsychotic drugs
• for those particularly at risk of failing to take their medication regularly some antipsychotic are available as injections once or twice a month
• may be requires in the short or long term depending on likelihood of symptoms reoccurring
  -antipsychotics can be divided into typical and atypical or second-generation drugs

Question 2

What are typical antipsychotics?

Answer 2

• drugs used to reduce the intensity of symptoms, in particular the positive symptoms, of psychotic conditions like schizophrenia
• by reducing dopamine production
• more side effects
• chlorpromazine is a typical antipsychotic drug that also acts as an effective sedative so is often given to patients when they first arrive in hospital

Question 3

What are atypical antipsychotics?

Answer 3

• these drugs have been used since the 1970s
• the aim in developing newer antipsychotic was to maintain or improve upon the effectiveness of drugs in supressing the symptoms of psychosis and also minimise the side effects
• examples of this is clozapine and Risperidone

Question 4

What is clozapine?

Answer 4

• clozapine discovered to be an effective atypical antipsychotic
• clozapine binds to dopamine receptors in the same way that chlorpromqazine does, but in addition it acts on serotonin and glutamate receptors
• it is believed that it helps improve mood and reduce depression and anxiety in patients

Question 5

What is risperidone?

Answer 5

-risperidone binds more strongly to serotonin and dopamine receptors than clozapine and is therefore effective in much smaller doses than clozapine and has fewer serious side effects

Question 6

What are the evaluation points of biological therapies?

Answer 6

+clozapine improves functioning and relapse rates in 50% of patients

• serious side effects of typical antipsychotics include facial ticks dizziness and even death
• antipsychotics are based on the dopamine hypothesis however the dopamine hypothesis is an incomplete explanation because high or low can cause schizophrenia
• atypical drugs may be inappropriate as they treat positive and negative symptoms of schizophrenia but a patient may only have one and not the other

Question 7

how does evidence for effectiveness support biological therapies?

Answer 7

• there is a large body of evidence to support the idea that both typical and atypical antipsychotic are at least moderately effective in tackling the symptoms for schizophrenia
• Thorley et al revived studies comparing the effects of chlorpromazine to control conditions in which patients received a placebo so their experiences were identical except for the presence of chlorpromazine in their medication
• data from 13 trials with a total of 1121 participants showed that chlorpromazine was associated with better overall functioning and relapse rate was also lower when chlorpromazine was taken
• in addition there is support for the benefits of atypical antipsychotic
• in a review Meltzer concluded that clozapine is more effective that typical antipsychotic and other atypical psychotics and that it is effective in 30-50% of treatment-resistant cases where typical antipsychotics have failed
• a number of studies have compared the effectiveness of clozapine and other atypical antipsychotics like Risperidone but results have been inconclusive, perhaps because some patients respond better to one drug than the other
• it does seem though that antipsychotic in general are reasonably effective and this is a strength

Question 8

How are serious side effects a weakness of biological therapies?

Answer 8

• typical antipsychotic are associated with a range of side effects like dizziness and agitation
• long-term use can result in dopamine super sensitivity causing involuntary facial movements
• the most serious side effect of typical antipsychotics is NMS casual by dopamine receptors being permanently blocked which can be fatal
• atypical antipsychotic can have some side effects so regular blood tests are taken

Question 9

How is the fact that the use of antipsychotic depends on the dopamine hypothesis a weakness of biological therapies?

Answer 9

• antipsychotics are based on the dopamine hypothesis
• however quite a bit of evidence to show that the dopamine hypothesis is not a complete explanation for schizophrenia and that in fact dopamine levels in parts of the brain other than the subcortex are too low rather than too high
• if this is true then it is not clear how antipsychotics which are dopamine antagonists can help with schizophrenia when they reduce dopamine activity in fact our modern understanding of the relationships between dopamine and psychosis suggests that antipsychotic shouldn’t work

Question 10

May not be appropriate?

Answer 10

• atypical drugs treat positive and negative symptoms

- a patient may only have one or another so the drug may not be appropriate