Biological Therapies for Schizophrenia

• Drug Therapy:


  The most common treatment for schizophrenia involves the use of antipsychotic drugs.Antipsychotics may be used in the short or long term.
• Typical Antipsychotics (1st generation)

  • Have been around since the 1950s
  • Examples include chlorpromazine
  • Typical antipsychotics act as dopamine antagonists.
  • Antagonists are chemicals which reduce the action of a neurotransmitter.
• How does dopamine Antagonists work?

  • Block the dopamine receptors on the postsynaptic neuron to reduce the action of dopamine.
  • When an individual takes chlorpromazine the dopamine levels increase, but then production is reduced.
  • This normalises the levels of dopamine in the brain and is linked to a reduction in the positive symptoms (eg. hallucinations and delusions).
• Sedation Effect (Chlorpromazine):

  • works as an effective sedative.
  • Used to calm individuals with schizophrenia and other conditions.
  • USed when individuals are first admitted to the hospital and very anxious.
  • Syrup is faster than tablets so it is normally in a syrup form.
• SIde effects of Typical Antipsychotics(chlorpromazine):

  • Dry mouth
  • COnsitipation
  • Lethargy
  • Tardive Dyskinesia ( sudden jerky movements)
• Atypical Antipsychotics (2nd Generation)


  These treatments are still used today and people having it have regular blood tests to ensure they are not developing agranulocytosis.Because of its potentially fatal side effects clozapine is not available as an injection and instead has slightly lower daily dosages. 
• How does Atypical Antipsychotics (Clozapine)work?

  • Binds to dopamine receptors, in the same way that chlorpromazine does, but also acts on serotonin and glutamate receptors.
  • Believed that this helps depression and anxiety in patients and improves cognitive functioning.
  • Reduces both positive and negative symptoms.
• Side effects of Clozapine:

  • Mood-enhancing effects of this drug mean its sometimes prescribed when an individual is at high risk of suicide. (30-50% of people with schizophrenia attempt suicide)
  • Weight gain, Cardiovascualr problems
• Effectiveness of Antipsychotics 


  Meltzer (2012) found that atypical antipsychotics are effective in 30-50% of treatment-resistant cases where typical antipsychotics have failed.

  This suggests that antipsychotics are effective in reducing the symptoms of schizophrenia.
• Limitation of ANtispychotic drugs (Side effects)

  Typical antipsychotics are associated with a range of side effects including dizziness, agitation and weight gain. Long-term use can lead to tardive dyskinesia. The most serious side effect is neuroleptic malignant syndrome, which results in a high temperature, delirium, comas and can be fatal.
• Limitation of Antipsychotics - Dont fully know how they work

  Understanding behind why antipsychotics work is based on the original dopamine hypothesis. However, we know now that this is not a complete explanation for schizophrenia and that it can be linked to low levels of dopamine in the cortex. If this is true, then most antipsychotics should not work.