Biologcal therapies for schizophrenia (drug therapy) Flashcards
what are antipsychotic drugs
the most common treatment for schizophrenia
for some people only a short course of drugs are required to stop symptoms, other people will require antipsychotics for life or else face the recurrence of schizophrenia
antipsychotics can be divided into typical and atypical drugs
what is the main typical antipsychotic
in the past typical antipsychotics were the main type of drug prescribed
chlorpromazine was the most common prescription
taken as tablets, syrup or injection
how does chlorpromazine work
acts as an antagonist in the dopamine system
blocks dopamine receptors in the synapses of the brain, reducing the action of dopamine
initially when an individual begins taking chlorpromazine dopamine levels build up, but then its production is reduced
normalises neurotransmission, this then reduces symptoms like hallucinations
explain chlorpromazine as a sedative
chlorpromazine produces a state of tranquillity (sedation) which is believed to be related to its effect on histamine receptors
often administered through syrup or injection when patients are first admitted to hospitals when they are anxious, so they are sedated
what is the supporting research for the effectiveness of typical antipsychotic drugs (strength)
Thornley (2003) reviewed studies comparing chlorpromazine to control conditions using a placebo
data from 1121 patients was analysed, findings indicated that those taking chlorpromazine showed better functioning and reduced symptoms
relapse rate lower
what are the serious side effects of typical antibiotics (limitation)
side effects such as dizziness, agitation and weight gain
long-term use can result in tardive dyskinesia, caused by dopamine super sensitivity and causes involuntary facial movements such as grimacing, blinking and lip-smacking
most serious side effect is neuroleptic malignant syndrome, caused by blockage of dopamine in the hypothalamus. this can be fatal
what are atypical antipsychotics
a more modern treatment with the aim of improving the effectiveness of treatment and reducing side effects
clozapine is a common atypical antipsychotic and is often used when other treatments failed
how does clozapine work
it binds to dopamine receptors in the same way chlorpromazine does, but it also acts on serotonin and glutamate receptors
this action is believed to help improve mood and reduce depression and anxiety
treats both positive and negative symptoms
how does risperidone work
improved version of clozapine but with fewer side effects
more effective in binding to dopamine receptors so can be prescribed in smaller quantities
what is the assumption of the accuracy of the dopamine hypothesis (limitation)
the basis of antipsychotic drugs is to control the action of dopamine, assuming levels are too high in the brain
recent studies have suggested that perhaps dopamine levels in the prefrontal cortex are too low
questions the idea that antipsychotics work by reducing dopamine activity
are antipsychotics being misused (discussion)
widely believed that antipsychotics have been used in hospital situations to calm people with schizophrenia and make them easier to work with, rather than the benefits to the patients themselves (Healy 2012)
this is viewed as having no effect on the psychotic symptoms
