drug therapies as treatment for schizophrenia Flashcards
what do schizophrenia drug treatments aim to do?
they aim to reduce the effect of dopamine in the brain. it is the most common type of treatment for schizophrenia
what are the 2 catagories of drug treatments?
typical/conventional antipsychotics
atypical antipsychotics
when were typical antipsychotics introduced and what is an example of one?
around since the 1950s
example: chlorpromazine
how do typical antipsychotics work?
they block the activity of the neurotransmitter dopamine and act as antagonists in the dopamine system. they do this by binding to the dopamine receptors on the post-synaptic neuron without activating it. when dopamine is then released into the synapse, most of the receptor sites are blocked.
what is the result of the dopamine levels after typical antipsychotics have been released into the synapse?
only a small amount of the dopamine released will have an effect on stimulating those parts of the brain.
which dopamine receptor does the antipsychotic tend to bind with?
D2 receptor, particularly in the mesolimbic dopamine region
when have atypical antipsychotics been around since and what are some examples?
been around since the 1970s
examples: clozapine, rispiridone
why were atypical antipsychotics introduced?
were produced to improve the effectiveness and reduce the side effects, however we don’t quite know how many work
how do atypical antipsychotics work?
they work in the same was as typical antipsychotics where they block the D2 receptors, however, they also effect other neurotransmitters (specifically serotonin). they also dissociate from their receptors quickly, allowing normal dopamine transmission in other parts of the brain which avoids the side effects.
how do atypical antipsychotics differ with negative symptoms compared to typical antipsychotics?
tend to be more effective with negative symptoms than typical antipsychotics
how do antipsychotics work within the synapse?
vesicles release the neurotransmitter (dopamine) into the synaptic cleft
antipsychotic attaches to the receptors without activating it, thus stopping the neurotransmitter (dopamine) from doing so
so, this reduces the action of the dopamine, meaning there is less activity in these parts of the brain.
AO3: how is ‘effectiveness’ a strength to drug therapies as a treatment to schizophrenia?
Leucht et al. (2012) carried out a meta analysis of 65 studies involving over 6000 patients with schizophrenia who had been stabilised on either typical/atypical antipsychotic drugs. some were switched to a placebo and the others stayed on the drug treatment. within the first year, 64% of the placebo patients relapsed, compared to 27% of the drug therapy. therefore, we can conclude that the drugs do have an effect, however, its not 100% so other factors may have influenced the relapse scores.
AO3: how is ‘effectiveness’ a limitation to drug therapies as a treatment for schizophrenia?
Birchwood and Jackson (2001) concluded that there was no found evidence that typical antipsychotic drugs are effective at treating the negative symptoms of schizophrenia. therefore, atypical antipsychotics are seen as better drug treatments than typical for negative symptoms, however there not that much better and other treatments may be found to be more useful in the stabilisation of schizophrenia.
AO3: how is ‘appropriateness’ a strength to drug therapies as a treatment for schizophrenia?
schizophrenia seems to have more of a genetic/biological basis than any other type of mental disorder; in particular, abnormalities in dopamine functioning. therefore, its appropriate to use a treatment where the main action is to block the dopamine activity, targeting the parts of the physiological system that appear to function abnormally in schizophrenics.
AO3: how are ‘side effects in typical antipsychotics’ a limitation to drug therapies as a treatment for schizophrenia?
Windgassen (1992) found that 50% of patients with schizophrenia taking typical antipsychotic medication reported grogginess and/or sedation, 18% reported problems with concentrating, 16% with blurred vision, 2% for neuroleptic malignant syndrome (muscle rigidity, altered consciousness, fever which can be fatal), 20% with tardive diskinesia when taking typical antipsychotics for over a year (involuntary sucking and chewing, jerky movements of limbs, writhing movements of face and mouth)
