Schizophrenia - Paper 3 Flashcards
Paper 3
How is Schizophrenia classified?
- The DSM-5 (The Diagnostic and Statistical Manual of Mental Disorders) published by the American Psychiatric Association (APA)
- The ICD – 10 (International Classification of Diseases) produced by the World Health Organisation (WHO).
What is criterion A for the classification of schizophrenia?
Two (or more) of the following symptoms must be present for a significant portion of time during a 1-month period.
At least one of these should include an active symptom (1- 3).
- Delusions
- Hallucinations
- Disorganised speech
- Grossly disorganised or catatonic behaviour
- Negative symptoms (i.e. diminished emotional expression or avolition)
What is criterion B for the classification of schizophrenia?
There should be a reduction in one or more major areas of functioning such as work, interpersonal relations or self-care.
What is criterion C for the classification of schizophrenia?
Continuous signs of the disturbance must persist for at least 6 months, during which the patient must experience at least 1 month of active symptoms.
What are the positive symptoms of schizophrenia?
Hallucinations and delusions
What are hallucinations?
These are unusual sensory experiences (visual, auditory, smell, touch or taste). About 70% of people with schizophrenia suffer from auditory hallucinations. Typically, the person hears a voice. This voice/voices may critically comment on their behaviour, warn them of future dangers, accuse them of something they did not do, or give orders
What are delusions?
There are irrational beliefs that have no basis in reality. Delusions can make a sufferer of schizophrenia behave in ways that make sense to them but seem bizarre to others.
What are delusions of persecution?
This is the belief that they are being spied on or plotted against by others such as the government.
What are delusions of grandeur?
This is when a person believes they are an important historical or religious figure, such as the queen or the pope.
What are the negative symptoms of schizophrenia
Speech poverty and avolition
How can you remember the difference between positive and negative symptoms?
Positive - behavioural excess
Negative - behavioural deficit
What is speech poverty?
This is a decrease in speech fluency and productivity. They produce fewer words in a given time on a task of verbal fluency (e.g. name as many animals as you can in 1 minute). This is not due to less verbal ability than people without schizophrenia, but more a difficulty spontaneously producing them. Patients will often slur their responses, not pronouncing consonants clearly and their words might trail off into a whisper.
What is avolition?
: A reduction of interests and desires as well an inability to initiate and persist in goal-directed behaviour. For example, sitting in the house for hours every day, doing nothing. Avolition is distinct from poor social functioning, which can be the result of other circumstances (e.g. having no friends and family available to have social contact with). To be classed as avolition, there must be a reduction in self-initiated involvement in activities that are available to the patient.
What is reliability in diagnosis and classification of schizophrenia?
Consistency in diagnosis. Whether there is agreement in the diagnosis of SZ by different psychiatrists across time and cultures. This is inter-rater reliability. It can be seen in whether diagnostic tests are consistent on different occasions - test-retest
What is a criticism of reliability of classification?
DSM and ICD tools are routinely used with a high level of reliability by mental health clinicians. Cheniaux (2009) asked two psychiatrists to independently diagnose 100 patients using both the DSM and the ICD. Inter-rater reliability was poor, for example, using the DSM, one psychiatrist diagnosed 26 patients with schizophrenia whilst the other only diagnosing 13. This a weakness of the diagnostic systems as they failed to produce consistent results and therefore shows that the reliability of diagnosing schizophrenia is poor.
What is co-morbidity? (reliability)
The presence of one or more additional disorders or diseases simultaneously occurring with SZ. substance abuse (47%), Anxiety/panic disorder (15%), symptoms of depression (50%). If a sufferer can experience simultaneous disorders this suggests that schizophrenia may not actually be a separate disorder. This could lead to different medical professionals giving different diagnoses of the same patient.
What is an evaluation point of comorbidity?
There is a large body of evidence to suggest that many sufferers do also have issues of substance abuse. Buckley (2009) found that around 50% of patients with schizophrenia also have depression or substance abuse. Alcohol, cannabis and cocaine are substances that can be abused by people with schizophrenia (possibly as a way of self-medicating) and not only does such co-morbid substance abuse make a reliable diagnosis of schizophrenia difficult to achieve, it also leads to lower levels of functioning, increased hospitalisations and lower compliance with medication, which makes effective treatment more difficult to achieve. This is a strength because it demonstrates the complexities involved in giving a reliable diagnosis if the person with schizophrenia is also using recreational drugs. Sufferers who use recreational drugs may find it difficult to achieve a reliable diagnosis as it’s difficult to know what symptoms are a direct effect of having schizophrenia and what are the symptoms of substance abuse.
What is culture bias in diagnosis and classification of SZ?
Culture bias reduces the validity of the diagnostic system. Both the ICD and DSM were developed by Western clinicians and are criticised for lacking cultural relativism. Therefore, people who show behaviours such as hearing voices, which may be normal in their own culture, are sometimes classified as having schizophrenia.
Culture bias can also affect the reliability of the diagnostic system. Research suggests there is a significant variation between cultures when it comes to diagnosing schizophrenia.
Copeland (1971) gave 134 US and 194 British psychiatrists a description of a patient. 60% of the US psychiatrists diagnosed schizophrenia, but only 2% of British ones did, showing diagnosis was unreliable across different cultures.
What is an evaluation point of culture bias in classification of SZ?
Research suggests that the diagnosis of schizophrenia is affected by culture bias. Pinto and Jones (2008) reported that in Haiti some people believe that voices are communications from ancestors. British people of African – Caribbean origin are up to nine times more likely to receive a diagnosis than white British people, although people living in African – Caribbean countries are not, ruling out a genetic vulnerability. This is a weakness of the diagnostic system because it highlights that the difference in diagnostic statistics of some cultural groups is due to the biased overinterpretations of symptoms by some psychiatrists.
What is validity in diagnosis and classification of SZ?
This is the extent to which the methods used to measure schizophrenia are accurately measuring schizophrenia. For example, the patient may have hallucinations but is not suffering with schizophrenia (symptom overlap and comorbidity) or it may be that psychiatrists are misinterpreting the behaviour of the patient (gender/culture bias). Additionally, different assessment systems (ICD/DSM) may arrive at completely different diagnoses. We can assess validity by using predictive validity - if a diagnosis leads to successful treatment, then diagnosis is seen as valid. The research findings on whether the diagnosis of schizophrenia is valid are very mixed. Some researchers report that when you match patients diagnosed with schizophrenia to the DSM criteria there is a good correlation (Hollis, 2000), suggesting that diagnosis is valid.
What is an evaluation point of validity in classification of SZ?
A threat to the validity of diagnosing schizophrenia is highlighted by the fact that in the same way that people diagnosed with schizophrenia rarely share the same symptoms, likewise there is no evidence that they share the same outcomes. The prognosis for patients diagnosed with schizophrenia varies with about 20% recovering their previous level of functioning. 10% achieving significant and lasting improvement, and about 30% showing some improvement with intermittent relapses. This is a problem because a diagnosis therefore, has little predictive validity because some people never appear to recover from the disorder, while many do.
What is the issue of gender bias in classification of SZ?
Gender bias in the diagnosis of schizophrenia occurs when the accuracy of diagnosis is dependent on the gender of an individual; the diagnostic criteria may be gender-biased or clinicians may base their judgments on stereotypical beliefs about gender.
Gender bias refers to the differential treatment of males and females in the diagnoses of schizophrenia. Statistically, since the 1980s, men are diagnosed with schizophrenia more often than women. It may be that due to genetic factors, women are genetically less vulnerable than men. However, it seems more likely that women are underdiagnosed because they are more likely to have support around them and therefore function better than men.
Cotton (2009) found that in patients with schizophrenia that female patients function better than male patients. E.g., they are more likely to work, and have good family relationships. This may explain why women are not diagnosed with schizophrenia as frequently as men. It appears that their better interpersonal functioning may bias clinicians to under-diagnose schizophrenia in women. This also explains why the age of onset tends to be much younger in males than in females.
What is an evaluation point of gender bias in sz?
Research suggests that gender bias is a problem in the diagnosis of schizophrenia and subsequent treatment offered. Evidence shows that males could be more likely to be committed to psychiatric institutions (referred to as being hospitalised) when they show mild signs of schizophrenia, due to the risk of socially deviant behaviour (e.g. violence). Females, on the other hand, are likely to be voluntary patients (even though they too spend some time in hospital) because they are more likely to seek help earlier. This is a strength as it supports the idea that gender differences in diagnosis exist. It appears that their better interpersonal functioning may bias clinicians to under-diagnose schizophrenia in women. This therefore threatens the validity of the diagnostic system because people may get an incorrect or no diagnosis based on their gender, rather than their symptoms.
What is symptom overlap?
This occurs when symptoms of schizophrenia are also found in other disorders. For example, positive symptoms, such as delusions and negative symptoms such as avolition occur in both schizophrenia and bipolar disorder. This makes it difficult for clinicians to accurately decide which particular disorder someone is suffering from when diagnosing.
What is the evaluation of symptom of overlap?
Research suggests symptom overlap can cause issues when accurately and reliably diagnosing schizophrenia.
Ophoff (2011) found a genetic overlap between bipolar disorder and schizophrenia. Three of the seven gene locations on the genome associated with schizophrenia were also associated with bipolar disorder. Both schizophrenia and bipolar disorder involve positive symptoms (such as delusions) and negative symptoms (such as avolition). This highlights the problem when trying to distinguish schizophrenia from other illnesses and in terms of classification this suggests that schizophrenia and bipolar disorder may not be two different conditions but variations of single condition.
What is a general evaluation point about the reliability and validity of classification and diagnosis of SZ?
A major consequence of invalid or unreliable diagnosis of SZ relates to the social stigma carried by being incorrectly labelled: Such inaccurate diagnosis can have a long-lasting negative impact on the lives of those diagnosed. Despite these problems, the classification systems do at least allow professionals to share a common language which helps in communicating ideas and also allows greater opportunities for research which can lead to a better understanding of schizophrenia.
What are biological explanations of SZ?
Dopamine hypothesis, enlarged ventricles, genetics