biological therapy

• drug therapy -

  • most common treatment involves the use of antipsychotic drugs
  • 'antipsychotic' prefers to psychosis - psychosis experiences some loss of contact with reality (hallucinations or delusions) - defining characteristic of schizophrenia
  • can be short term or long term use
  • some can take a short course without return of symptoms
  • others may require antipsychotics for life or else face likelihood of reccurance
  • typical (traditional) and atypical (newer)
• typical antipsychotics -

  • around since 1950s
  • chlorpromazine - taken as tablets, syrup or injection
  • if taken orally it is administered daily up to a maximum of 1000mg
  • initially doses are gradually increases to maximum of 400-800mg
  • typical prescribed doses have declined over last 50 years
• typical antipsychotics: dopamine antagonists -

  • strong association between use of typical antipsychotics and the dopamine hypothesis
  • work by acting as antagonists in dopamine system - antagonists are chemicals which reduce the action of a neurotransmitter
  • dopamine antagonists work by blocking dopamine receptors in synapses of brain, reducing action of dopamine
  • initially when taking chlorpromazine dopamine levels build up, then production is reduced
  • dopamine-antagonist effect normalises neurotransmission in key areas of the brain, reducing symptoms like hallucinations
• typical antipsychotics: sedation effect -

  • chlorpromazine is an effective sedative - believed to be related to its effect on its histamine receptors
  • used to calm individuals
  • often when patients are first admitted to hospitals and are very anxious
  • syrup is absorbed faster than tablets so it tends to be given when chlorpromazine is used for its sedative properties
• atypical antipsychotics -

  • used since the 1970s
  • aim in developing newer antipsychotics was to maintain or improve upon the effectiveness of drugs in suppressing the symptoms of psychosis and minimise side effects of drugs used
  • range of atypical antipsychotics and they don't all work in the same way
• atypical antipsychotics: clozapine -

  • 1980s discovered to be more effective than typical antipsychotics
  • people have regular blood tests to ensure they're not developing agranulocytosis - a fatal blood condition
  • daily dosage lower - 300-400mg a day
  • binds to dopamine receptors but also serotonin and glutamate receptors - believed this action helps improve mood and reduce depression and anxiety in patients + improve cognitive functioning
  • mood-enhancing so sometimes prescribed to people at risk of suicide - 30-50% of schizophrenics attempt
• atypical antipsychotics: risperidone -

  • around since 1990s - developed to attempt to produce drug as effective as clozapine but without serious side effects
  • taken as tablets, syrup or injection that lasts around 2 weeks
  • initially small dose and built up to typical daily dose of 4-8mg
  • believed to bind to dopamine and serotonin receptors - binds more strongly than clozapine and is therefore effective in much smaller doses
  • evidence that this leads to fewer side effects than other antipsychotics