Schizophrenia - Therapies for Schizophrenia Flashcards
What are the key features of typical antipsychotics?
- Dopamine antagonists.
- Block dopamine receptors in the synapse.
- Chlorpromazine also has a sedation effect.
What are typical antipsychotic drugs?
Typical antipsychotic drugs (e.g. chlorpromazine) have been around since the 1950s.
They work by acting as antagonists in the dopamine system and aim to reduce the action of dopamine - they are strongly associated with the dopamine hypothesis.
How do dopamine antagonists work?
Dopamine antagonists work by blocking dopamine receptors in the synapses in the brain, reducing the action of dopamine.
Initially, dopamine levels build up after taking chlorpromazine, but then production is reduced.
This normalises neurotransmission in key areas of the brain, which in turn reduces symptoms like hallucinations.
How does chlorpromazine have a sedation effect?
Chlorpromazine also has an effect on histamine receptors which appears to lead to a sedation effect.
Therefore it is also used to calm anxious patients when they are first admitted to hospital.
What are the key features of atypical antipsychotics?
- Target dopamine and serotonin.
- Clozapine acts on dopamine, glutamate and serotonin to improve mood.
- Risperidone is as effective as clozapine but safer.
What are atypical antipsychotics?
Atypical antipsychotics (e.g. clozapine) have been used since the 1970s.
The aim of these drugs was to improve the effectiveness of drugs in suppressing psychoses such as schizophrenia and also minimise the side effects.
They typically target a range of neurotransmitters including dopamine and serotonin.
What is clozapine?
Clozapine binds to dopamine receptors as chlorpromazine does but also acts on serotonin and glutamate receptors.
This drug was more effective than typical antipsychotics - clozapine reduces depression and anxiety in patients as well as improving cognitive functioning.
It also improves mood, which is important as up to 50% of people suffering from schizophrenia attempt suicide.
What is risperidone?
Risperidone was developed because clozapine was involved in the deaths of some patients from a blood condition called agranulocytosis.
Ripseridone like clozapine binds to dopamine and serotonin receptors.
But risperidone binds more strongly to dopamine receptors and is therefore more effective in smaller doses than most antipsychotics and has fewer side effects.
What are the strengths of biological therapies for schizophrenia?
- evidence shows antipsychotics are moderately effective
- research is scientific, and uses objective and measurable results
- it means that patients can be treated in the community rather than being institutionalised for life
What are the weaknesses of biological therapies for schizophrenia?
- there are serious side effects, ranging from mild to fatal
- theoretical objection to the use of antipsychotic drugs
- doubts about the true effectiveness of antipsychotics
- antipsychotic drugs may simply be a ‘chemical cosh’
- ethical issues as it is difficult for patients to give informed consent
- antipsychotics don’t deal with the cause of schizophrenia, but instead work at hiding the symptoms
What evidence shows antipsychotics are moderately effective?
Thornley et al. (2003) reviewed data from 13 trials (1121 participants) and found that chlorpromazine was associated with better functioning and reduced symptom severity compared with a placebo.
There is also support for the benefits of atypical antipsychotics. Meltzer et al. (2012) concluded that clozapine is more effective than typical antipsychotics, and that it is 30-50% more effective in treatment-resistant cases.
Therefore the evidence suggests that antipsychotics are reasonably effective.
What side effects are there to antipsychotic drugs?
Typical antipsychotics are associated with dizziness, agitation, sleepiness, weight gain, etc. Long-term use can lead to lip-smacking and grimacing due to dopamine super-sensitivity.
The more serious side effect is neuroleptic malignant syndrome (NMS) caused by blocking dopamine action in the hypothalamus (can be fatal due to disrupted regulation of several body systems).
Atypical antipsychotics were developed to reduce side effects but some still exist and this is a serious limitation of antipsychotic drug therapies.
What theoretical objection is there to the use of antipsychotic drugs?
The use of these drugs is strongly tied up with the dopamine hypothesis and the idea that there are higher than usual levels of dopamine in the subcortex in the brain.
But there is evidence that this may not be correct and that dopamine levels in the other parts of the brain are too low rather than too high. If so, antipsychotics shouldn’t work.
This has undermined the faith of some people that any positive effects are actually due to the pharmacological effects of antipsychotics.
What doubts are there about the true effectiveness of antipsychotics?
Healy (2002) suggests that data from some successful trials have been published multiple times, exaggerating the positive effects. Also, most studies only review short-term effects.
Healy also suggests that as antipsychotics have powerful calming effects, it is easy to demonstrate that they have a positive effect on patients despite the fact they may not be effective in reducing psychosis.
This suggests that the effectiveness of antipsychotics may be overestimated by much of the empirical research.
How may antipsychotic drugs be a ‘chemical cosh’?
Antipsychotics may have been used in hospital situations to calm patients and make them easier for staff to work with, rather than to benefit the patients themselves.
Short-term use of antipsychotics to calm patients is recommended by the National Institute for Health and Care Excellence.
However, this practice is seen by some as a human rights’ abuse, and raises ethical issues in the use of antipsychotic drugs with schizophrenia patients.
What are the 3 different psychological therapies for schizophrenia?
- cognitive behaviour therapy
- family therapy
- token economies
What is the aim of cognitive behaviour therapy?
The aims of CBT in general are to help patients identify irrational thoughts and try to change them.
This may involve discussion of how likely a patient’s beliefs are to be true, and consideration of less threatening possibilities.
How does cognitive behaviour therapy help patients?
Patients are helped to make sense of how their delusions and hallucinations impact on their feelings and behaviour.
For example, a patient may hear voices and believe they are demons so they will be very afraid.
Offering explanations for these symptoms reduces anxiety and helps the patient realise their beliefs are not based on reality.
What is the aim of family therapy?
Family therapy is with families rather than individual patients, aiming to improve communication and interaction in the family.
Family therapists try to reduce stress within the family that may contribute to patient’s risk of relapse (e.g. reduce levels of expressed emotion).
What strategies are used in family therapy?
Pharaoh et al. (2010) identified a range of strategies family therapists use to reduce the likelihood of relapse and readmission to hospital. For example:
- Reduce stress of caring for a relative with schizophrenia.
- Improve ability of family to anticipate and solve problems.
- Reduce guilt and anger in family members.
- Improve beliefs about and behaviour toward schizophrenia.
What are token economies?
Token economies are reward systems (operant conditioning) used to manage the behaviour of patients with schizophrenia who spend long periods in psychiatric hospitals.
Tokens (e.g. coloured discs) are given to patients who carry out desirable behaviours (e.g. getting dressed, making a bed, etc.).
This reward reinforces the desirable behaviour and because it is given immediately prevents ‘delayed discounting’ (reduced effect of a delayed reward).
How are tokens secondary reinforcers?
Tokens have no value in themselves but can be swapped later for tangible reward (e.g. sweets, a walk outside, etc.).
They are secondary reinforcers because they only have value due to the learned association (classical conditioning) with innate primary reinforcers.
What are the weaknesses of psychological therapies for schizophrenia?
- research shows limited benefits
- psychological therapies may help but not cure
- ethical issues
- quality of some evidence is low
- alternative psychological therapies are under-researched
How does research show limited benefits for psychological therapies?
Jauhar et al. (2014) found CBT had a significant but small effect on positive and negative symptoms. McMonagle and Sultana (2009) found only one of three studies of token economies that used random allocation showed improvement.
Pharaoh et al. reviewed effectiveness of family therapy and found moderate evidence for the reduction of hospital readmissions over one year and some improvement to quality of life - but the evidence was inconsistent.
Overall there us only modest support for the effectiveness of psychological therapies.
