Biological Therapies Flashcards
What are antipsychotics?
Drugs used to reduce the intensity of positive symptoms of psychotic conditions.
What are the two types of antipsychotics?
Typical and atypical.
What are typical antipsychotics?
The first generation of antipsychotic drugs. They target dopamine reducing the positive symptoms of schizophrenia.
What are atypical antipsychotics?
The second generation of antipsychotic drugs. They target dopamine and serotonin, reducing positive and negative symptoms of schizophrenia.
How do typical antipsychotic drugs work?
They act as dopamine antagonists in that they bind to dopamine receptors at the postsynaptic neuron and block the action of dopamine.
Why are there less side effects with atypical antipsychotics?
Typical antipsychotics bind more tightly than dopamine itself to the dopamine D2 receptor, with dissociation constants that are lower than that for dopamine. The newer atypical antipsychotics all bind more loosely than dopamine to the dopamine D2 receptor and have dissociation constants higher than that for dopamine. This means they transiently occupy D2 receptors and then rapidly dissociate to allow normal dopamine transmission.
How do atypical antipsychotic drugs work?
Also act as dopamine antagonists, but they also block the action of serotonin.
What is an example of a typical antipsychotic and max dose?
Chlorpromazine. Max 1000mg a day
What are 2 examples of an atypical antipsychotic and max doses?
Clozapine and Risperidone. Max 450mg a day
Which type of antipsychotic causes severe side effects and examples
Typical antipsychotics.
Dizziness, restlessness, sedation.
Movement problems that resemble Parkinsons. Symptoms begin gradually, sometimes with a barely noticeable tremor in the hand.
LT use can result in Tardive Dyskinesia. This is a condition where your face or body makes sudden irregular movements you cannot control.
2 Strengths (1 COUNTER) of biological therapies for schizophrenia
Leuch et al. (2012)- carried out a meta-analysis involving nearly 6,000 patients- some taken off their antipsychotic medication and given a placebo instead. The remaining patients remained on their regular antipsychotics. Within 12 months, 64% of placebo patients had relapsed, compared to 27% of those who stayed on the antipsychotic drug.
COUNTER - It is also suggested that because antipsychotics have powerful calming effects, it is easy to demonstrate that they have some positive effect on patients. This is not the same as saying they really reduce the severity of psychosis.
Research into biological therapies allows us to improve their effectiveness.
A key advantage of atypical antipsychotics that were developed later is that patients experience fewer side effects- less likely to result in movement problems commonly found with typical antipsychotics. As a result patients are more likely to continue with their medication, which in turn means they are more likely to see a reduction in their symptoms.
2 Limitations of biological therapies for schizophrenia
Typical antipsychotics can produce severe side effects for the patient:
These drugs reduce dopamine levels which is responsible for movement. Therefore, side effects include serious movement problems. More than HALF of the people who take these drugs experience side effects. The most common resembling the neurological disorder Parkinsons and can lead to Tardive Dyskinesia in which your face and body male sudden irregular movements that cannot be controlled.
Motivational deficits associated with taking drugs;
It is argued that when people are prescribed antipsychotic, it prevents the individual from thinking about possible stressors (such as life history or current circumstances) that might be contributing to their condition. In turn this reduces their motivation to look for possible solutions that might alleviate these stressors and reduce their suffering.
As human misery is largely inflicted by other people then the best solutions are usually human interventions, rather than chemical.
