Biological Therapy for Schizophrenia

• Typical Antipsychotics

  eg Chlorpromazine since 1950s in high doses

  Dopamine antagonists - reduce action of neurotransmitter dopamine normalising neurotransmission in key areas and reducing hallucinations

  Sedation effect - chlorpromazine has a sedative effect to calm down patients who are anxious in hospital - syrup is absorbed faster than tablets so was often used
• Atypical AP - Clozapine

  Developed in 1960s but not used due to link to agranulocytosis

  used in 1980s as research showed more effective than other drugs

  Bids to DA receptors as well as serotonin and glutamate so is used to treat accompanying depression and low mood in pts high risk of suicide
• Atypical AP - Risperidone

  developed in 1990s for effect of clozapine without side effects

  taken in tablet, syrup or biweekly injection (2 weeks)

  Binds more strongly to DA receptors than clozapine and is more effective so smaller doses needed (4-8 mg vs 300-450mg)
• A03: Evidence of Effectiveness

  +Research showing antipsychotics are effective treatments

  Thornley - meta-analysis of comparisons between chlorpromazine and placeboes across 13 trials with 1121 ppts - finding better functioning and reduced symptom severity when on the drug

  Some may not respond well to typical antipsychotics

  Meltzer - clozapine was effective in 30-50% of treatment cases where typical AP were ineffective

  so both show AP effectiveness but also value of many avenues of treatment available
• A03: Effectiveness counter

  -Issues with drug trials

  Healy - many trials focus on short-term but SZ is a lifelong condition

  so patients now must take medication log term with unknown long term effects leading to side effects and withdrawal

  Successful trials are republished multiple times - inaccurate depiction leading to unmerited confidence in effectiveness

  AP calm patients with sedative effect - treating psychosis or just making patients more docile?
• A03: Serious side effects

  -accompanied by a range of serious side effects

  short term dizziness, agitation, stiff jaw, itchy skin, and long term use leads to tardive dyskinesia causing involuntary facial movements

  Typical AP are also linked to neuroleptic malignant syndrome by blocking DA in hypothalamus leading to delusions, coma and death

  all side effects increase social isolation and stigma

  question if drugs are actually used to help patients or just to benefit society
• A03: Mechanism unclear

  -Theory they are based on suggests they should not be effective

  Reduce Da so in line with original DA hypothesis

  However in updated, hypoDA also present meaning hypothesis is incorrect or AP doesn't treat root cause of SZ

  Mechanism of drug action is unclear and some other factor may be involved in symptom reduction