Schizophrenia evaluation Flashcards
Reliability and validity evaluation
Reliability- Cheniaux asked two psychiatrists to diagnose 100 patients using the DSM and the ICD and found that the inter-rater reliability was poor which is a weakness because the diagnostic systems failed to produce consistent results
Comorbidity- Buckley found that around 50% of patients with SZ also have depression or substance abuse which led to lower levels of functioning, increased hospitalisations and lower compliance. This is a strength as it shows how complex diagnosing SZ is and how difficult it is to get a reliable diagnosis
Culture bias- Pinto and Jones reported that in Haiti some people believe hearing voices is communication from ancestors. British people of African-Caribbean descent are nine times more likely to be diagnosed with SZ than white British people but people living in African-Caribbean countries are not which shows a weakness because it highlights the difference in diagnosis is due to biased interpretations
Validity- there is no evidence that people with SZ share the same outcomes and the prognosis for people with SZ varies with about 20% recovering their previous level of functioning and a variation of 10% achieving lasting improvement which is a problem because it shows little predictive validity so some may recover but some may not
Gender bias- evidence shows that males are more likely to be hospitalised but females are likely to be voluntary patients and more likely to seek help earlier this is a strength as it supports the idea that gender differences in diagnosis exist
Symptom overlap- Ophoff found a genetic overlap between bipolar disorder and SZ of 3/7 genes + both involve positive and negative symptoms which highlights the problem of trying to differentiate between them/ they may not be two different conditions but a variation of one condition
Dopamine hypothesis evaluation
Strength- Wong used PET scans and found an increase in the number of dopamine receptors in several brain regions of patients with SZ this is a strength because it supports the view that SZ is caused by high levels of dopamine receptors/ dopamine levels
Strength- support from drug studies e.g. cocaine increases dopamine levels causing schizophrenic like symptoms in normal people + Parkinson’s disease is caused by a lack of dopamine so they are given a drug to increase dopamine but if the dosage is too high the patients suffer from schizophrenic like side effects. This supports the view that dopamine is the primary cause of many schizophrenic symptoms
Strength- the dopamine hypothesis has led to the creation of anti-psychotic drugs e.g. chlorpromazine which reduces dopamine so reduces positive symptoms. This is a strength because it strengthens the validity of the dopamine hypothesis
Enlarged ventricles evaluation
Strength- Yoon used fMRI scans to examine the brains of 18 patients with SZ and 19 without SZ performing a memory task and found that the SZ pts had decreased activity in the prefrontal cortex and lack of connectivity between other parts of the brain the stronger the symptoms of SZ were. This is a strength as it increases scientific credibility of the idea that abnormal functioning of the prefrontal cortex is related to cognitive deficits
Limitation- much of the evidence to support neural correlates is correlational therefore cause and effect cannot be established and it is possible that actually schizophrenic symptoms cause the brain changes
Limitation- neural correlates is no longer accepted as a complete explanation and the use of the diathesis stress model might be more appropriate e.g. faulty levels of dopamine make the person vulnerable to SZ but it must be triggered by a stressful life event
Genetic explanation evaluation
Strength- supporting evidence from twin studies e.g. there is a concordance rate of 40% for MZ twins and 7% for DZ twins which shows there must be some genetic influence in developing SZ as MZ twins share 100% of their DNA
Strength- supporting evidence from family studies e.g. Varma found that 16% of first degree relatives of someone with SZ also developed SZ compared to 7% of the controls which shows that the closer the genetic relatedness is to someone with SZ the greater the chance of developing it yourself
Strength- supporting evidence from adoption studies e.g. Tienari compared adopted children whose biological mothers had SZ compared to a control group without any genetic risk and found a higher rate of SZ amongst the children with a mother who had SZ. This is a strength because despite the environmental influence of the mother with SZ being removed, the genetic risk was still evident
Drug therapy evaluation
Strength- supporting evidence for atypical antipsychotics e.g. Meltzer who concluded that clozapine was 30-50% more effective in treating resistant cases of SZ than typical antipsychotics. This supports the idea that SZ is caused by a chemical imbalance and the drug therapy corrects that
Limitation- serious side effects like Tardive dyskinesia (involuntary chewing, sucking, jerky movements) which can be permanent and is found in 30% of people taking antipsychotics. In 75% of cases this is irreversible and is a weakness as it stops sufferers from taking the medication and suggests that drug therapy is not the most effective method
Limitation- side effects can lead to problems with patient compliance and it is argued that 50% of SZ patients stop taking their medication after a year which leads to revolving door syndrome (pt regularly relapses, is admitted for care and treated successfully with drugs but then avoids taking them again when released so the cycle repeats) this is a weakness as it questions how appropriate the drugs are long-term for a stable recovery
Family dysfunction evaluation (psychological explanation)
Strength- supporting evidence from Tienari for high expressed emotion (adoption study with adoptees who had SZ mother) then he found that when the parenting style of the adoptive family was highly critical with low levels of empathy it increased the risk of SZ and vice versa with empathetic families (risk was reduced)
strength- Berger found supporting evidence for the double bind hypothesis as SZ pts reported higher recall of double bind statements from their mothers than non-SZ pts which shows that contradictory messages may increase risk of SZ
Strength- real world applications e.g. the development of family therapy and decreased chances of relapse (26% compared to 50% in a group who didn’t receive family family)
Cognitive explanation evaluation
Strength for dysfunctional thought processing- Stirling completed a task with 30 SZ pts and 30 non-SZ pts where they had to name the font colours of colour words and he found that people with SZ took twice as long on average than the control group to name the font colours
Strength- real world applications of CBTp which has been extremely effective in treating SZ even more so than drug therapy as it reduces symptoms without side effects and improves social functioning
Limitation- antipsychotic medication could be the cause of cognitive impairments and not SZ + neural correlates and abnormal dopamine levels could be the cause of cognitive impairments and not cause SZ which casts doubt on the belief that cognitions are to blame
CBTp evaluation
Strength- supporting evidence from Tarrier who reviewed 20 studies using CBTp and found that CBTp persistently reduced positive symptoms, relapse rates and increased rate of recovery in the short term
Limitation- many pts with severe SZ drop out of CBTp e.g. Tarrier found that 45% of the sample refused to cooperate or dropped out during the trial as pts need to be highly motivated and put in time and effort for the therapy to be successful and suffering with avolition doesn’t allow that
Limitation- the effectiveness of CBTp is increased when it is mixed with other treatments like drug therapy e.g. Addington and Addington found that following stabilisation of symptoms with medication, people with SZ can benefit from group-based CBT to normalise their experience. This is a weakness because CBT might only be useful for specific stages of treatment and may need to be constantly adapted
Family therapy evaluation
Strength- Pharaoh carried out a meta analysis on 53 studies to compare family therapy to drug therapy and found that family therapy reduced the risk of relapse, hospitalisation and increased compliance with medication. This is a strength as it suggests that better family relationships are key to recovery
Strength- provides therapists with insight into the pts SZ as family members can assist with providing info about the pts SZ in a coherent way if the pt is unable to do so themselves
Limitation- Garety found little difference in the improvement of symptoms of SZ in pts who received family therapy compared to pts that received no family therapy but had carers with low EE. This shows that low levels of EE are also important in improving symptoms but it also shows that family therapy might not be necessary if a high quality of care is provided
Token economy evaluation
Strength- Głowacki identified 7 studies published between 1999-2013 and reported that all studies had shown a reduction in negative symptoms and a decline in the frequency of unwanted behaviours after token economy therefore supporting the idea that they are a good management technique
Limitation- token economy is only really effective in treating negative symptoms which involve social withdrawal but cannot be effective in treating positive symptoms like hallucinations as they cannot learn to stop seeing/ hearing unusual things
Limitation- can be viewed as manipulative and unethical as privileges from token economy will become more accessible only to pts with milder symptoms + Corrigan claimed that token economies can be abusive and humiliating as it allows others to have power over the patient
Interactionist approach for explaining SZ evaluation
Strength- Tienari study with adoptees who had SZ mothers (mentioned before)
Strength- supporting evidence from twin studies as genetic inheritance has a role but the concordance rates are not 100% so the environment must also play a role
Interactionist approach for treating SZ evaluation
Strength- Tarrier studied 315 pts who were randomly allocated to
1. Medication and CBT
2. Medication and counselling
3. Control group (medication only)
He found that symptoms were lower in both combination groups therefore an Interactionist approach might have more benefits
Limitation- using combination treatments makes it difficult to identify which treatment is the most successful and beneficial for the patient + evidence shows that combinations are most effective but we don’t know which treatment is having the greatest effect
