Biological treatments

• Outline biological treatments for SZ

  There are two types of antipsychotics which are used to treat SZ - typical and atypical.
• How do antipsychotics work

  Antipsychotics are dopamine antagonists because they bind to complementary dopamine receptors

  on the postsynaptic membrane, thus preventing dopamine molecules from binding to these sites. The result is an inhibitory effect, where there is a lower rate of action potential generation in the postsynaptic membranes, and so returns neurotransmission (e.g. in the prefrontal cortex and subcortices) to a normal level.
• What are typical antipsychotics

  Typical antipsychotics are described as 'first generation' because these were the drugs historically prescribed to treat SZ patients. The main example of a typical antipsychotic would be Chlorpromazine. It is particularly favoured in psychiatric institutions due to its calming and sedative effects, due to acting upon histamine receptors in addition to dopamine receptors.
• What are atypical antipsychotics

  Atypical antipsychotics are described as 'second generation' because they were developed to add to the effectiveness of first generation medications, and also alleviate the serious side effects associated with such drugs.

  
  

  Atypical antipsychotics work in the same way as typical antipsychotics, but also target other neurotransmitter receptors on postsynaptic membranes, in line with more modern research. For example, Clozapine targets serotonin and glutamate receptors, whilst Risperidone acts on dopamine and serotonin receptors.
• What does clozapine do?

  The key advantage of Clozapine is the improvements in cognitive functioning and mood which patients experience when taking it. This is particularly useful considering that SZ has a 50% comorbidity rate with depression - however, these benefits may be offset by the serious side effect of agranulocyotis, which is a severe and dangerous leukopenia which has caused several deaths in the past.
• What does risperidone do?

  key advantage of Risperidone is that smaller doses are required because it acts more strongly on dopamine receptors compared to Clozapine, and so would be particularly suited to patients who do not suffer from depression but have a previous history of blood-related illnesses.
• What are the strengths of drug therapy

  Ben Thornley et al reviewed 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.Chlorpromazine was associated with better functioning and reduced symptom severity.Data from three trials showed that relapse rate was lower when the drug was taken.

  
  

  Drugs are easy to take, affordable and popular with patients due to the familiarity of taking pills and lack of effort needed

  
  

  schizophrenics could return to work which helps the economy
• What are the weaknesses of drug therapy

  Drugs do not address the cause of a problem, merely its symptoms, and so once the medication is stopped, the symptoms are likely to recur

  
  

  Side effects