schizophrenia: bio treatment - drugs Flashcards
1
Q
how does the biological approach explain mental disorders?
A
- in terms of abnormalities of the central nervous system e.g. that there is something wrong with the workings of the brain
- e.g. schizophrenia has been explained as being caused by an excess of the neurotransmitter dopamine and depression has been explained as being caused by a deficiency of the neurotransmitter serotonin
2
Q
what treatment is used based upon the dopamine hypothesis?
A
- drug therapy
- conventional antipsychotics aim to reduce the positive symptoms of schizophrenia
- these drugs bind to the dopamine receptors, but do not stimulate them
- this blocks the sites meaning that the dopamine cannot affect the neurons
3
Q
what medication is used for schizophrenia? what are the two main phases? what problems could there be?
A
- antipsychotic medications are prove effective in treating acute psychosis and reducing the risk of future psychotic episodes
- the treatment for schizophrenia this has two main phases:
- an acute phase, when higher doses might be necessary in order to treat psychosis symptoms, followed by a maintenance phase, which is usually *life-long**
- during maintenance phase, dosage is often gradually reduced to the minimum required to prevent further episodes and control inner-episode symptoms
- if symptoms reappear or worsen on a lower dosage, an increase in dosage may be necessary to help prevent further relapse
- even with continued treatment, some patients experience relapses
- the most common cause of a relapse is stopping medications
4
Q
how is drug therapy used? what are the problems with this?
A
- an important step forward in the 1950s, as it can mean people who are suffering from schizophrenia can in many cases allow normal functioning
- doctors will usually prescribe a typical anti-psychotic medication, such as chlorpromazine or haloperidol, following the first psychotic episode
- they will only try one drug at a time and monitor the patient carefully for changes in symptoms and any side effects
- drug treatments need to be started quickly in order to be most effective, and those patients who remain untreated for many years often do not benefit when treatments are finally started
- if symptoms do not improve with the use of typical anti-psychotics, then an atypical anti-psychotic such as clozapine or risperidone might be used
- individual patients react differently to different treatments and doctors have their own preferences which they may develop through experience with many patients and hence it is not as simple as there being one drug per disorder
5
Q
what do anti-psychotic drugs do within schizophrenia?
A
- they work to suppress hallucinations and delusions
6
Q
what are the two anti-psychotic drugs known as?
A
- typical (first-generation antipsychotics FGAs)
- atypical (second-generation antipsychotics SGAs)
7
Q
what are typical antipsychotic drugs?
A
- well-established
8
Q
what are atypical antipsychotic drugs?
A
- newer and less widely used
- tend to have fewer side effects and act in different ways to typical
- seem to be better for negative symptoms and for improving cognitive functioning
9
Q
how long do antipsychotic drugs take to reduce positive symptoms?
A
- about 2 weeks
10
Q
how can a patient take antipsychotics?
A
- in syrup or tablet form
11
Q
what happens when a patient forgets to take antipsychotic drugs?
A
- then medical practitioners could inject the anti-psychotics
12
Q
what are the side effects of antipsychotic drugs?
A
- sleeping and tiredness
- shaking and muscle spasms
- low blood pressure
- problems with sex drive
- weight gain
13
Q
what is chlorpromazine? (typical/atypical, how it works, side effects/risk of relapse, research studies)
A
- typical
- blocks dopamine receptor sites and thus decreases dopamine activity
- muscle tightening in the neck and jaw, tardive dyskinesia, decrease of spontaneous movement, decrease in emotional spontaneity and motivation, motor restlessness and fidgeting, sedation, dry mouth, constipation, weight gain, neuroleptic malignant syndrome (can be fatal)
- Barlow + Durand 1995: chlorpromazine is effective is reducing schizophrenic symptoms in about 60% of cases. most impact on positive symptoms; treated patients may still suffer from severe negative symptoms
14
Q
what is haloperidol? (typical/atypical, how it works, side effects/risk of relapse, research studies)
A
- typical
- blocks dopamine receptor sites and thus decreases dopamine activity
- 55% relapse rate in Schooler et al 2005 study. side effects: muscle tightening in the neck and jaw, tardive dyskinesia, decrease of spontaneous movement, decrease in emotional spontaneity and motivation, motor restlessness and fidgeting, sedation, dry mouth, constipation, weight gain, neuroleptic malignant syndrome (can be fatal)
- Schooler et al 2005: randomly allocated 555 patients in first episode of schizophrenia, to either treatment with haloperidol or risperidone. in both groups 75% showed a reduction in symptoms
15
Q
what is clozapine? (typical/atypical, how it works, side effects/risk of relapse, research studies)
A
- atypical
- blocks both dopamine and serotonin receptor sites
- similar side effects to typical anti-psychotics but tardive dyskinesia much reduced. fewer side effects than typical or first-generation antipsychotics. rare side effect: agranulocytosis, (dangerously low levels of white blood cells) can be fatal
- Pickar et al 1992 compared clozapine with other neuroleptics and a placebo and found clozapine to be the most effective in reducing symptoms, even in patients who had previously been treatment resistant
