Biological Therapies for SZ

• Typical Antipsychotics


  Example: Chlorpromazine

  how they're administered: pill or syrup forms and dosages vary to up a maximum of 1,000mg. option for an injection

  how they work: conventional antipsychotics are 'dopamine antagonists'

  bind to D2 receptors without stimulating them so reduces action of dopamine.

  dopamine hypothesis - dopamine antagonist effect normalises neurotransmission in key areas of brain and can stop hallucinations
• Atypical Antipsychotics


  Example 1: Clozapine -> stopped using used when found it caused a blood condition.

  how they're administered: not an injection (potential fatal side effects). pill/syrup

  how it works: binds to dopamine receptors like chlorpromazine but works on serotonin and glutamate receptors.

  believed to help reduce depression and anxiety in patients and may improve cognitive functioning.

  Example 2: Risperidone -> developed to be as effective as clozapine, without the fatal side effects.

  how they're administered: syrup, pill or injection that lasts 2 weeks

  typical doses start at 4-8mg with a maximum dosage of 12mg

  how it works: binds to dopamine and serotonin receptors. it binds more strongly to dopamine receptors than clozapine.
• Weakness - many elements contradict dopamine hypothesis

  can we be sure the drugs are helping all symptoms of SZ? according to the dopamine hypothesis, not all symptoms require dopamine to be reduced.

  E.g. low levels of dopamine in prefrontal cortex can increase negative symptoms such as speech poverty and avolition.

  Therefore, drug can't be a dependable form of treatment for SZ.
• Weakness - only treat the symptoms not the causes

  E.g. drop out rates for antipsychotics are very high due to their side effects. this means that when SZ patients can no longer take the medication, they're forced to live with SZ symptoms as antipsychotics hadn't treated the cause but only reduced the symptoms. In a medical situation, they can use antipsychotics to calm symptoms.

  Therefore, SZ patients are easier to work with supporting idea they're not used to treat the cause.
• Weakness - drugs cause more harmful side effects

  For example, neuroleptic malignant syndrome (NMS) which is characterised by rise in temperature, delirium and potential coma. This is fatal and is worse than SZ itself. Often, it does more harm as it causes psychological harm to not only the sufferer but also family or friends.

  Therefore, when choosing to administer antipsychotics, side effects of the drug should be weighed against its effectivity.
• Strength - evidence to suggest antipsychotics are successful

  Thornley et al reviewed chlorpromazine studied 13 trials with 1,200 ppts. the studies showed that chlorpromazine lead to better functioning and ppts showed slower relapse rates with chlorpromazine.

  Strength - produces credibility for biological treatments and effective SZ treatments.
• Potential Side Effects


  drowsiness

  weight gain

  tremors

  sexual dysfunction