Schizophrenia: drug treatment Flashcards
What are the 2 main types of antipsychotics
- typical antipsychotics
- atypical antipsychotics
What are typical antipsychotics
- the first generation of antipsychotics (developed during the 1950s). They work as dopamine antagonists (e.g. Chlorpromazine).
what are antagonists?
- An antagonist blocks or reduces the effect of a neurotransmitter.
What are atypical antipsychotics
- 2nd generation of antipsychotics (developed during the 1990s).
- They typically target a range of neurotransmitters such as dopamine and serotonin (e.g. Clozapine & Risperidone).
Explain how typical antipsychotics (chlorpromazine) are used to treat schizophrenia
- used to calm patients especially when admitted to hospital.
- Initially the dopamine builds up in the brain, then production is reduced.
- According to the hypothesis, this dopamine-antagonist effect normalises neurotransmission -> reduced symptoms such as hallucinations.
Explain how atypical antipsychotics (clozapine) are used to treat schizophrenia
- used when other treatments have failed.
- daily dosage is between 300-450mg per day.
- Helps mood and reduces depression and anxiety.
Explain how atypical antipsychotics (risperidone) are used to treat schizophrenia
- Developed in 1990s as an attempt to reduce side effects of clozapine.
- Smaller doses are given from 4-8mg up to 12mg per day.
- Binds to dopamine and serotonin receptors -> However, it has a stronger binding effect on dopamine than clozapine and is effective in lower doses.
list the evaluations for drug treatment for schizophrenia
Positive
- Evidence for effectiveness
Negative
- serious side effects
- use of antipsychotics depends on the dopamine hypothesis
- problems with evidence
- chemical chosh argument
(+) explain how there is evidence of effectiveness of drug treatment for schizophrenia (Thornley)
- Thornley et al. (2003) reviewed studies comparing the effects of chlorpromazine to control conditions - patients in this control condition 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.
(+) explain how there is evidence of effectiveness of atypical antipsychotics for schizophrenia (Meltzer)
- Meltzer (2012) concluded that clozapine is more effective than typical antipsychotics and other atypical antipsychotics.
- Effective in 30-50% of cases.
- Meltzer also stated that other atypical antipsychotics have been developed to reduce side effects and have succeeded.
(-) Explain how there are serious side effects
- some side effects are mild but can be fatal: dizziness, agitation, sleepiness, stiff jaw, weight gain and itchy skin.
- Typical antipsychotics can produce ‘Tardive dyskinesia’ (uncontrollable movements of face, lips, mouth, tongue as well as other areas of the body.)
(-) explain how use of antipsychotics depends on the dopamine hypothesis
- has been found that schizophrenia results from much higher levels of dopamine activity in the subcortex.
-> However not a complete explanation for schizophrenia. - Levels were too low (in other parts of the brain) rather than too high.
- therefore, not clear whether an antagonist can help with schizophrenia symptoms as dopamine levels in the sub cortex can be too low rather than too high.
(-) explain how there are problems with evidence for the effectiveness of drug treatments
- Healy (2012) has suggested that over publication has lead to misleading positive evidence.
- Due to the drugs calming effects, it can be concluded that they help patients with schizophrenia, but do they actually reduce the severity of psychosis?
- Most publications discuss short term rather than long term benefits.
(-) explain the chemical cosh argument
- chemical cosh: sedation of an individual with chemicals or a medication, especially where sedation is unnecessary.
- NICE recommend using antipsychotics to calm patients, but could this be of benefit to staff rather than patient.
-> human rights abuse
-> Ethics
(-) Explain how there is evidence refuting use of antipsychotics (antipsychotics vs placebos, Ross and Read)
- Davis analysed results of 29 studies, found relapse occurred in 55% of patients whose drugs were replaced by a placebo, 19% of those who remained on the drug relapsed.
- Ross and Read say these figures are misleading -> also indicate that 45% of those on a placebo did benefit (100%-55%).
- Likewise, the 81% (100%-19%) who benefitted from the drug, the data suggest that a large proportion (i.e. 45%) would also have benefitted from a placebo.