Biological treatment

• What drugs are used to treat SZ?

  Antipsychotics
• How are antipsychotics administered?

  Tablets, injection, syrup
• What are the 2 types of antipsychotics?

  • Typical (older)
  • Atypical (newer)
• What are typical antipsychotics?

  • 1950’s first generation drug.
  • E.g Chlorpromazine
  • Tablets start with a lower dose e.g 400 mg and increase to 800mg
• How do typical antipsychotics work?

  • Linked to dopamine hypothesis
  • They aim to block dopamine receptions: reduces dopamine so reduces symptoms of SZ.
  • Initially, causes a build-up of dopamine levels but then production decreases to reduce the levels.
• What other effects can chlorpromazine have?

  • Sedative effect
  • Can be used to calm patients when first admitted to hospital
• Explain the effects of antipsychotics using the dopamine hypothesis.

  • The dopamine hypothesis suggests SZ symptoms are associated with high levels of dopamine.
  • Antipsychotic drugs are dopamine antagonists.
  • They work by binding to dopamine receptors, leading to a reduction in dopamine production.
  • This reduction in dopamine production leads to a decline in the symptoms of SZ.
• Example of atypical antipsychotics

  • Clozapine
• What are atypical antipsychotics?

  • Used since 1970’s
  • AIM is to suppress symptoms of SZ and minimise the side effects.
• Clozapine

  • Developed in 1960‘s, first trailed in 1970’s.
  • Was withdrawn in 1970’s following deaths from agranulocytosis.
  • It was discovered to be more effective than typical antipsychotics and was used in other treatments failed.
  • But involves having regular blood tests to ensure they are not developing agranulocytosis
• How does clozapine work?

  • Clozapine binds to dopamine receptors the same way as chlorpromazine does, but in addition acts on serotonin and glutamate receptors.
  • helps to improve mood, improve cognitive functioning, reduce depression and anxiety in patients.
  • As it improves mood is it sometimes prescribed to those at risk of suicide.
• Atypical antipsychotics

  • Clozapine
  • Risperidone
• Risperidone

  • Been around since 1990’s
  • Can take the form of tablets, syrup or an injection
  • Binds to dopamine and serotonin receptors
  • Binds more strongly to dopamine receptors than clozapine and is effective in much smaller doses than other antipsychotics.
  • Leads to fewer side effects.
• Evidence for effectiveness

  • Thornley reviewed studies comparing the effects of chlorpromazine to control conditions where patients received a placebo.
  • Data from 13 trials with a total of 1121 participants showed that chlorpromazine was associated with better overall functioning and reduced symptom severity. Relapse rates were low when chlorpromazine was taken.
  • Antipsychotics are an effective form of treatment for SZ.
• Serious side effects

  • Typical antipsychotics linked to dizziness, agitation and weight gain. Prolonged use can lead to tardive dyskinesia (condition resulting in facial movements such as grimacing, blinking, lip smacking. Patients taking Clozapine must have regular blood tests to alert doctors to early signs of agranulocytosis.
  • Both types are effective however pose risks of harm.
  • Therefore the side effects can lead to other medical problems which will compromise patient quality of life.
• Sedative effect

  • Antipsychotics such as chlorpromazine have powerful sedative effects as well as antipychotic properties, so can be used to make initially distressed and occasionally aggressive patients controllable.
  • Making it easier for hospital staff to work with SZ patients. Additionally by relieving symptoms like hallucinations and delusions it makes it easier for sufferers to engage in other treatments like CBT.
  • Allow hospital staff and psychologists to provide effective treatment
• Use of antipsychotics is dependant on the dopamine hypothesis

  • Original dopamine hypothesis suggested there is high levels of dopamine activity in the sub cortex of the brain. but recent evidence has shown that the original dopamine hypothesis is not the complete explanation of SZ as there are areas in the brain where dopamine levels are low.
  • Based on hypodopaminergia, antipsychotics would not work as they aim to reduce dopamine levels not increase dopamine levels.
  • Therefore, antipsychotics may not be the most effective form of treatment.