Schizophrenia

Question 1

What is schizophrenia?

Answer 1

• schizophrenia is a serious mental disorder suffered by about 1% of the world population
• it is more commonly diagnosed in men than women, more commonly diagnosed in cities than the countryside and in working-class rather than middle-class people
• the symptoms of schizophrenia can interfere severely with everyday tasks, so that many sufferers end up homeless or hospitalised

Question 2

What is classification of schizophrenia?

Answer 2

• schizophrenia does not have a single defining characteristic
• it is a cluster of symptoms some of which appear to be unrelated
• the two major systems for the classification of mental disorder, are the world health organisation’s internal classification of disease edition 10 (ICD-10) and the American Psychiatric association’s diagnostic and statistical manual edition 5 (DSM-5/DSM-V)
• these differ slightly in their classicisation of schizophrenia
• for example in the DSM-5 system one of the so-called positive symptoms - delusions and hallucinations or speech disorganisation - must be present for diagnosis whereas two or more negative symptoms are sufficient under ICD
• ICD-10 recognises a range of subtypes of schizophrenia
• Paranoid schizophrenia is characterised by powerful delusions and hallucinations but relatively few other symptoms
• the defining characteristic of catatonic schizophrenia is disturbance to movement, leaving the sufferer immobile or alternatively overactive
• previous editions of the DSM system also recognised subtypes of schizophrenia but this has been dropped in DSM-5

Question 3

What are positive symptoms of schizophrenia?

Answer 3

• positive symptoms of schizophrenia are additional experiences beyond those of ordinary existence, they include hallucinations and delusions
• hallucinations
• delusions

Question 4

What are hallucinations?

Answer 4

• these are usual sensory experiences
• some hallucinations are related to events in the environment whereas others bear no relationship to what the senses are picking up from the environment, for example, voices heard either talking to or commenting on the sufferer, often criticising them
• hallucinatio0ns can be experienced in relation to any sense
• the sufferer may, for example see distorted facial expressions or occasionally people or animals that are not there

Question 5

What are delusions?

Answer 5

• also known as paranoia, delusions are irrational beliefs
• these can take a range of forms
• common delusions involve being an important historical, political or religious figure, such as Jesus or napoleon
• delusions also commonly involve being persecuted, perhaps by government or alien or of having superpowers
• another class of delusions concerns the body
• sufferers may believe that they or part of them is under external control
• delusions can make a sufferer of schizophrenia behave in ways hat make sense to them but seem bizarre to others
• although the vast majority of sufferers are not aggressive and are in fact more likely to be victims than perpetrators of violence, some delusions can lead to aggression

Question 6

What are negative symptoms of schizophrenia?

Answer 6

• negative symptoms of schizophrenia involve the loss of usual abilities and experiences -abolition
• speech poverty

Question 7

What is abolition?

Answer 7

• sometimes called apathy, can be described as finding it difficult to begin or keep up with goal-directed activity, i.e. actions performed in order to achieve a result
• sufferers of schizophrenia often have sharply reduced motivation to carry out a range of activities
• Anderson identified three identifying signs of abolition; poor hygiene and grooming, lack of persistence in work or education and lack of energy

Question 8

What is speech poverty?

Answer 8

• schizophrenia is characterised by changes in patterns of speech
• the ICD-10 recognises speech poverty as a negative symptom
• this is because the emphasis is on reduction in the amount and quality of speech in schizophrenia
• this is sometimes accompanied by a delay in the sufferer’s verbal responses during conversation
• nowadays, however the DSM stem places its emphasis on speech disorganisation in which speech becomes incoherent or the speaker changes topic mid-sentence
• this is classified in DSM-5 as a positive symptom of schizophrenia, whilst speech poverty remains as a negative symptom

Question 9

What are the evaluation points of schizophrenia?

Answer 9

• poor inter raters reliability between DSM 5 and ICD 10, combination = 30, just DSM = 30, 40 = ICD another psychologist diagnosed 10 using DSM and 20 using ICD
• validity of ICD and DSM as they give different diagnosis pseudo experiment rejected real patients and accepted 8 normal people
• co morbidity means 50% of people were also diagnosed with schizophrenia and 20% were diagnosed with OCD
• schizophrenia has the same positive symptoms as bipolar disorder like delusions suggesting symptom overlap

Question 10

How is reliability a weakness schizophrenia?

Answer 10

• Cheniaux et al had two psychiatrists independently diagnose 100 patients using both DSM and ICD criteria
• inter-rater reliability was poor, with one psychiatrist diagnosing 26 patients using both DSM and ICD criteria
• inter-rater reliability was poor, with line psychiatrist diagnosing 26 with schizophrenia according to DSM and 44 according to ICD, and the other diagnosing 13 according to DSM and 24 according to ICD
• this poor reliability is a weakness of diagnosis of schizophrenia

Question 11

How does validity support schizophrenia?

Answer 11

• validity is the extent to which we are measuring what we are intending to measure
• in the case of a mental disorder like schizophrenia there are a number of validity issues to consider
• one standard way to assess validity of diagnosis is criterion validity; do different assessment systems arrive at the same diagnosis for the same patient?
• looking at the figures in the Cheniaux et al study above we can see that schizophrenia is much more likely to be diagnosed using ICD than DSM
• this suggests that schizophrenia is either over-diagnosed in ICD or under-diagnosed in DSM
• this suggests that schizophrenia is either over-diagnosed in ICD or under-diagnosed in DSM
• either way, this is poor validity - a weakness of diagnosis

Question 12

How is co-morbidity a weakness of schizophrenia?

Answer 12

• schizophrenia is commonly diagnosed with other conditions
• in one review Buckley et al concluded that around half of patients with a diagnosis of schizophrenia also have a diagnosis of depression or substance abuse
• post-traumatic stress disorder also occurred in 29% of cases and OCD in 23%
• this poses a challenge for both classification and diagnosis of schizophrenia
• in terms of classification, it may be that, if very server depression looks a lot like schizophrenia and vice versa, then they might be better seen as a single condition

Question 13

How is symptom overlap a weakness of schizophrenia?

Answer 13

• there is considerable overlap between the symptoms of schizophrenia and other conditions
• for example, both schizophrenia and bipolar disorder involve positive symptoms like delusions and negative symptoms like abolition
• this again calls into question the validity of both the classification and diagnosis of schizophrenia
• under ICD a patient might be diagnosed as a schizophrenic; however many of the same patients would receive a diagnosis of bipolar disorder according to DSM criteria
• this is unsurprising given the overlap of symptoms
• it even suggests that schizophrenia and bipolar disorder may not be two different conditions but one