A01: Biological Therapy for SZ

• Biological Therapy for SZ

  • Typical Antipsychotics
  • Atypical Antipsychotics
• Typical Antipsychotics: Dopamine antagonists:

  Typical antipsychotic drugs (e.g. chlorpromazine) been around since the 1950s.

  • Work by acting as antagonists in dopamine system
  • Aim to reduce action of dopamine - they associated with dopamine hypothesis.
  • Dopamine antagonists work by blocking dopamine receptors in the synapses in the brain, reducing action of dopamine.
  • Initially, dopamine levels build up after taking chlorpromazine but then production reduced. This normalises neurotransmission in key areas of brain, which reduces symptoms like hallucinations.
• Atypical Antipsychotics: Newer Drugs:


  • The aim of developing newer antipsychotics was to maintain or improve upon the effectiveness of drugs in suppressing the symptoms of psychosis and also to minimise the side effects of the drugs used.
• Drugs are the treatment most commonly used for SZ. There are many factors which will affect treatment plans - these factors are?

  • Severity
  • Co-Morbidity
  • Memory (remembering to take them)
  • Symptom types
  • Side effects
  • Compliance (willingness to take drug)
• Drugs differ in?

  • Format (pill/injection etc)
  • Frequency
  • Type
  • Dosage
• Although drug treatments seem flawed & dangerous compared to other modern treatments, its important to recognise how much they have alleviated the suffering that comes with Sz: Ways that antipsychotic drugs would be superior to these early psychiatric treatments.

  • Effects not necessarily permanent (unlike lobotomies)
  • Drugs ore ethical - less dehumanising
  • Easier to take = more people take them (have more motivation to take them)
  • Lower risk & less invasive/intrusive (no surgery)
  • More economical
• Typical vs Atypical Antipsychotics?

  Typical antipsychotics tend to more strongly block dopamine. Atypical antipsychotics have greater effects on serotonin.  (CHECK)
• Antipsychotics

  • Clozapine (ATYPICAL)
  • Chlorpromazine (TYPICAL)
  • Risperidone (ATYPICAL)
• Clozapine

  • Atypical (2nd generation antipsychotic)
  • Developed 1960s, trialled 1970s (withdrawn few years 1970s coz agranulocytosis deaths
  • Daily frequency
  • Format: table, syrup (not injection coz more risk of agranulocytosis)
  • Dosage: 300-450mg tablet
  • MORE effective vs typical

  Mode of Action:

  • Binds to dopamine receptors same way as chlorpromazine, acts on serotonin & glutamate receptors
  • Thought to improve cognitive functioning, mood, lower anx, depr in Sz sufferers, key up to 50% of sz people attempt suicide. More likely prescribed patient considered suicide risk.
• Chlorpromazine

  • Typical antipsychotic drug
  • First used in 1950s
  • Daily frequency
  • Format: Tablets, syrup / an injection
  • Dosage: 400-800mg (max 1000 mg daily)

  Mode of Action

  • Acts as dopamine antagonist: binding to dopamine receptor & blocking reuptake of dopamine.
  • Initially cause build up of dopamine but eventually this diffuses & dopamine production reduces.

  Other properties:

  • Also has sedation effect due to its action on histamine receptors & can have a secondary effect of calming anxious patients when they first admitted to hospital. When needed for this syrup used not tablets.
• Risperidone

  • Atypical Antipsychotic drug
  • First used in 1990s because clozapine was involved in the deaths of some people from a blood condition called agranulocytosis.
  • Daily frequency
  • Format: tablets, syrup or injections that last for 2 weeks
  • Dosage: 4-8mg daily dosage (max 12mg)

  Mode of Action:

  • Bind to dopamine & serotonin receptors like Clozapine
  • Bind more strongly to dopamine vs Clozapine so more effective in smaller doses than most antipsychotics and has fewer side effects.
  • Risperidone is as effective as clozapine but safer: