biological therapy for schizophrenia

• Antipsychotics


  Drugs used to reduce the intensity of symptoms, in particular the positive symptoms, of psychotic disorders like schizophrenia
• Typical antipsychotics


  The first generation of drugs for schizophrenia and other psychotic disorders, having been used since the 1950s. They work as dopamine antagonists and include chlorpromazine.
• Atypical antipsychotics


  Drugs for schizophrenia (a psychotic disorder) developed after typical antipsychotics. They typically target a range of neurotransmitters such as dopamine and serotonin. Examples include clozapine and risperidone.
• drug therapy

  • antipsychotic drugs
  • short or long terms
  • typical or atypical drugs
• typical antipsychotics

  • since the 1950s
  • e.g chlorpromazine
  • taken as tablets, syrup or injection
  • orally - daily max 1000 mg - normally smaller than increased gradually
• typical antipsychotics - dopamine antagonists

  • chlorpromazine work by acting as antagonists in the dopamine system
  • reduces the action of a neurotransmitter
  • block dopamine receptors in the synapses of the brain - reducing the action
  • normalises neurotransmission - reduces hallucination
• typical antipsychotics - sedation effect

  • chlorpromazine - sedative
  • effect on histamine receptors
  • often used to calm individuals in hospitals
• atypical antipsychotics

  • used since 1970s
  • maintain or improves upon the effectiveness of drugs in suppressing the symptoms of psychosis and minimise the side effects if the drugs used
• atypical antipsychotics

  • clozapine
  • risperidone
• atypical antipsychotics - clozapine

  • developed 1960s
  • treatment for schizophrenia when other treatments failed
  • fatal side effect - not available as injection
  • lower daily dosage
  • binds to dopamine receptors but also acts on serotonin and glutamate receptors - improves mood and reduces depression and anxiety
  • improves cognitive function
  • prescribed when an individual is considered at high risk of suicide
• atypical antipsychotics - risperidone

  • 1990s
  • produced as a drug as effective as clozapine but without side effects
  • tablets, syrup, injection - small dose given then built up to max of 12mg
  • bind dopamine and serotonin receptors
  • binds more strongly to dopamine receptors - smaller doses
  • fewer side effects
• AO3 - drug therapy - strength

  P: evidence to support their effectiveness

  E: Thornley - reviewed studies comparing the effect of chlorpromazine to control conditions - 13 trials - 1121 ppts showed that it was associated with better functioning and reduced symptom severity compared to placebo

  Meltzer - clozapine effective in 30-50% of treatment-resistant cases where typical antipsychotic failed

  L: Antipsychotics work
• AO3 - drug therapy - limitation

  p: likelihood of side effects

  E: typical = dizziness, agitation, sleepiness, stiff jaw, weight gain and itchy skin

  can even lead to involuntary facial movements

  Neuroleptic malignant syndrome - drug blocks dopamine action in the hypothalamus which is associated with the regulation of several body systems

  high temp, coma and even death

  L: antipsychotics can do harm as well as good and individuals who experience these may avoid such treatments - cost-benefit
• AO3 - drug therapy - limitation

  P: we do not know why they work

  E: our understanding is tied up with the original dopamine hypothesis - but this is not a complete explanation for schizophrenia

  dopamine levels in other parts of the brain are too low

  E: so antipsychotics should realistically not work - may be ineffective

  L: may not be the best treatment to opt for - may be some other factor involved