Biological treatments of SZ Flashcards
what are the two different forms of anti psychotic medication for treatments of schizophrenia?
- typical
-atypical
- medication must be taken on a regular basis to keep symptoms under control and takes about 7 days for the medication to take effect and reduce symptoms. initially positive symptoms are dramatically reduced and slowly negative symptoms.
what are the names of the different TYPICAL anti psychotic drugs?
- Chlorpromazine
what is the name of an ATYPICAL drug??
- Clozapine / Risperidone
what is an antagonist and agonist drug?
- antagonist = drug that binds to receptor on primary site or another which stops receptor from producing a response
- agonist = drug that binds to receptor, producing similar response to intended chemical and receptor
explain how the typical drug chlorpromazine / Haloperidol effects schizophrenia?
- Name: Chlorpromazine / Haloperidol
- Aim: To antagonise (reduce) levels of dopamine in the brain.
- Action: By binding to D2 receptor sites, this lowers dopamine transmission and reduces some positive symptoms. Kapur (2000) approx. 60-75% of D2 receptors were blocked in mesolimbic pathway.
- Potential problems: As the 60-75% D2 receptor sites were (permanently) blocked, dopamine levels become too low in the mesolimbic and mesocortical pathways. This can aggravate negative motor symptoms.
Other side effects are similar to atypical antipsychotics (MESOLIMBIC PATHWAY
explain how the atypical drugs effect schizophrenia??
- Name: Clozapine / Risperidone (MESOLIMBIC PATHWAY + NIGROSTRIATAL PATHWAY)
- Aim: To modulate levels of dopamine and serotonin in key dopamine pathways in the brain.
- Action: To regulate functioning of dopamine and serotonin in several areas by blocking D1, D2, D4 and 5-HT2 receptors.
- Side Effects: weight gain / decreased libido / drowsiness etc.
Tardive dyskinesia (TD) is a condition where your face, body or both make sudden, irregular movements which you cannot control. This is a side-effect of all antipsychotic medications that is potentially irreversible in affected patients. Newer atypical antipsychotics are felt by many to have a lower risk of TD.
explain how drugs affecting the mesolimbic dopamine pathway helps treat SZ?
This sensory pathway is involved with emotions and sensations of pleasure.
Reducing the hyperactivity of dopamine here should reduce positive symptoms like delusions.
By using a hit and run action (rapid dissociation) AP have their effect on dopamine receptors and then quickly leave the receptor site.
This type of action allows AP to have an effect, but then receptors quickly become available for naturally occurring dopamine before the next dose.
This action helps avoid some motor side effects.
explain how drugs affecting the nigrostriatal sensory pathways helps treat SZ?
This sensory pathway has a role in controlling movement, and as such involves dopamine and serotonin.
The blocking / reducing of dopamine receptor sites here can lead to negative motor side effects.
However, serotonin presence in this pathway antagonises/ inhibits (reduces) dopamine release, so the AP’s action is to block serotonin receptors to actually increase levels of natural dopamine in dopamine receptors in this pathway and in the prefrontal cortex.
Hence, natural dopamine fills receptor sites and prevents blockade from AP’s in this area.
This helps tackle negative symptoms and reduces motor side effects.
what are the positive evaluations for biological treatments?
- There is research support.
Davis et al (1980) analysed the results of 29 studies (with 3519 patients) looking into the effectiveness of antipsychotics for psychotic conditions such as schizophrenia.
They found that relapse occurred in 55% in schizophrenic patients whose antipsychotic drugs were replaced by a placebo, compared to just just 19% relapsed when they were still taking their antipsychotic medication.
However, Ross and Read (2004) point out that these figures could be misleading, as they also indicate that 45% of schizophrenic patients taking placebos did actually benefit from this. Likewise, of the 81% of those who benefitted from the drug, the data suggests that a large number of these (i.e. 45%) would have also benefited from a placebo.
Therefore… - Biological treatment may be more useful as as part of a wider treatment option, as the success of antipsychotics at treating schizophrenia can be increased when combined with more traditional psychological therapies.
The medication could suspend delusionary thoughts, allowing patients to address the more cognitive and family issues related to schizophrenia through CBT for example (Kopelowicz & Liberman, 1998). This is shown to increase the effectiveness in treating schizophrenia.
This suggests that… an interactionist approach to treating schizophrenia is more useful, by combining antipsychotic medication and psychological therapy, and could have a significant improvement on the quality of life of individuals with the disorder.
what are the negative evaluations for biological treatments??
- However, they are not completely effective in treating all individuals with schizophrenia.
In a longitudinal study design Elesser et al. (1996) discovered that antipsychotics should not be thought of as a cure for schizophrenia, even though they can eliminate some symptoms and make psychotic experiences less intense and distressing.
They do not help everyone, and rarely remove all symptoms of schizophrenia. The more typical antipsychotics help about 65% of those treated whilst atypical drugs help about 85% of patients. This is especially true as the half life for antipsychotics is around 24 hours.
This could imply… that biological treatments are limited as they do not actually ‘cure’ SZ therefore a more effective treatment option may be needed for schizophrenia so that we can help more individuals. - There are many side effects of this treatment, which presents an ethical dilemma for clinicians, i.e., patients with schizophrenia are not protected from harm.
One side effect is a condition known as tardive dyskinesia, which affects about 60% of patients taking antipsychotics, which is largely irreversible (APA, 2000). This is a debilitating disorder characterised by involuntary ‘jerky’ bodily and facial movements, e.g., lip smacking and tongue thrashing.
The side effects of atypical antipsychotics also include weight gain, cardiovascular problems and agranulocytosis (autoimmune disorder affecting white blood cells).
This is a weakness of antipsychotics to treat schizophrenia as patients may choose not to take the medication to avoid the side-effects, reducing its effectiveness. Davison & Neale (1998) found that 50% stop taking these drugs after one year and up to 75% after two years due to the side effects.
Therefore…
-Compare with other treatments eg. CBT
STARTUP et al (2004) investigated the effectiveness of CBT, by recruiting 90 patients who had been admitted to hospital with an acute episode. 43 were given standard care i.e. antipsychotics and nursing care, whilst the other 47 were given standard care plus up to 25, 90 minute sessions of CBT.
They found that 60% of CBT group showed reliable and clinical improvement, with fewer positive AND negative symptoms, compared to 40% of the control group (antipsychotics).
More importantly, these benefits stood the test of time and remained at 6 and 12 month follow ups, compared to just 17% of the control group.
