Biological treatments

• Drug therapy

  The most common treatment for SZ is the use of antipsychotic drugs

  They may be required in short-term or long-term

  There is typical and atypical antipsychotics
• Typical antipsychotics

  used since the 1950s

  chlorpromazine can be taken as tablets, syrup or injections.

  if taken orally, it's administered daily with a max of 1000mg, initial doses are much smaller a usually gradually increased to a max of 400-800 mg

  typical prescribed doses have declined over the last 30 years
• Dopamine antagonists  

  There is a strong association between the use of typical antipsychotics like chlorpromazine and the dopamine hypothesis

  chlorpromazine works by acting as antagonist in the dopamine system to reduce action of neurotransmitter by blocking dopamine receptors in the synapse of the brain reducing the action of dopamine.
• Sedation effect 

  As well as having antipsychotic properties chlorpromazine is also an effective sedative.

  This is believed to be related to its effect on histamine receptors but it is not fully understood how this leads to sedation.

  Chlorpromazine is often used to calm individuals not only with schizophrenia but also with other conditions.

  This has often been done when patients are first admitted to hospitals and are very anxious.
• Atypical antipsychotics

  have been used since the 1970s. 

  The aim in developing newer antipsychotics was to maintain or improve upon the effectiveness of drugs in suppressing the symptoms of psychosis and also minimise the side effects of the drugs used. 

  There are a range of atypical antipsychotics and they do not all work in the same way. In fact we do not know how some of them work.
• clozapine

  Clozapine binds to dopamine receptors, in the same way that chlorpromazine does, but in addition it acts on serotonin and glutamate receptors.

  It is believed that this action helps improve mood and reduce depression and anxiety in patients, and that it may improve cognitive functioning. The mood-enhancing effects of clozapine mean that it is prescibed when there’s a high risk of suicide.

  This is important as 30 to 50% of people with schizophrenia attempt suicide at some point.
• A strength is evidence to support the idea that antipsychotics are effective

  reviews of studies comparing the effects of chlorpromazine to control conditions, a total of 1121 participants showed that chlorpromazine was associated with better overall functioning and reduced symptom severity as compared to placebo.

  Meltzer concluded that clozapine is more effective than typical antipsychotics and other atypical antipsychotics, and that it is effective in 30-50% of treatment resistant cases where typical antipsychotics have failed
• A limitation is they’re associated with a range of side effects like dizziness, agitation, sleepiness, stiff jaw, weight gain and itchy skin.

  It can cause neuroleptic malignant syndrome, caused when the drug blocks dopamine action in the hypothalamus, an area associated with the regulation of a number of body systems, it can result in high temp, delirium and coma and can be fatal 

  antipsychotics can do harm as well as good and individuals who experience these may avoid such treatment, making the treatment inaffective