Diagnosis of Schizophrenia

Question 1

What is a Sz?

Answer 1

A serious mental disorder suffered by about 1% of the world population. It can severely interfere with everyday life so many sufferers end up homeless or hospitalised

Question 2

Who is Sz more common in?

Answer 2

More common in men than women, in cities than countryside and in working class rather than middle class people

Question 3

What are the two major system for the classification of mental disorders?

Answer 3

The ICD-10 and DSM -5

Question 4

How do the ICD-10 and DSM-5 differ?

Answer 4

DSM you need to have one positive symptom such as delusions, hallucinations or speech disorganisations to be diagnosed whereas two or more negative symptoms are sufficient under ICD
ICD recognises a range of subcultures

Question 5

What are some different types of schizophrenia?

Answer 5

Paranoid Sz is characterised by powerful delusions and hallucinations but relatively few other symptoms
The defining characteristic of catatonic Sz is disturbance of movement leaving the sufferer immobile or alternatively overactive

Question 6

What did the DSM previously recognise?

Answer 6

Different sub-types of Sz but this is no longer the case in the new DSM

Question 7

What are positive symptoms?

Answer 7

These are additional to ordinary existence

Question 8

What are hallucinations?

Answer 8

These are unusual sensory experiences. Some are related to events in the environment where others are not, for example voices heard talking (usually criticising)
They can be related to any sense e.g. see distorted facial expressions or people/animals that aren’t there

Question 9

What are delusions?

Answer 9

Also known as paranoid delusions, are irrational beliefs
Delusions make sufferers behave in a way that makes them appear bizarre, most sufferers are not aggressive and are more likely than not to be sufferers of violence

Question 10

What are examples of common delusions?

Answer 10

Involve famous people such as Jesus or Napoleon
Being persecuted e.g. by the government or aliens
Also may involve parts of the body where the sufferer believes that they or part of them may be under control

Question 11

What are negative symptoms?

Answer 11

Involves the loss of usual abilities include avolution and speech poverty

Question 12

What is avolution?

Answer 12

Sometimes known as apathy (can be described as finding it difficult to begin or keep up with a goal directed activity
Andreason identified three identifying signs of avolition; poor hygiene and grooming, lack of interest in work and education and a lack of energy

Question 13

What is speech poverty?

Answer 13

Sz is characterised by changes in speech patterns
The ICD-10 recognises speech poverty as a negative symptom
This is because an emphasis is on reduction in the amount and quality of speech in Sz

Question 14

What does DSM place emphasise on in terms of speech?

Answer 14

Speech disorganisation in which speech becomes incoherent or the speaker changes topic mid-sentence. in DSM-5 this is a positive symptom while speech poverty remains negative

Question 15

What is reliability?

Answer 15

Means for something to be consistent
An important measure is inter-rater reliability which is the extent to which different assessors agree on the same diagnosis for the same patients

Question 16

What was Ellie Cheniaux’s research into reliability?

Answer 16

She had two independent psychiatrists independently diagnose 100 patients using DSM and ICD
Inter-rater reliability was poor with one psychiatrist diagnosing 26 with Sz 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 in diagnosis

Question 17

What is validity and how is it measured?

Answer 17

The extent to which we are measuring what we set out to measure
Criterion validity is used to see if using separate systems to diagnose come to the same outcome. We see that Sz is much more likely to be diagnosed using ICD. This means a weakness of diagnosis

Question 18

What is co-morbidity?

Answer 18

The phenomenon that two or more conditions occur together

Question 19

What is the problem with co-morbidity?

Answer 19

If conditions occur together a lot of the time then this calls into question the validity of their diagnosis and classification because they might actually be a single condition
In terms of clarification if very severe depression looks a lot like Sz and vice versa, then should they be viewed as a single condition - this confusion makes for a weak diagnosis and classification

Question 20

How many people with Sz are also diagnosed with other conditions?

Answer 20

Buckley et al concluded that half the patients with a Sz diagnosis also have depression (50%) or substance abuse (47%)
PTSD also occurred in 29% of cases and OCD in 23%

Question 21

What is symptom overlap?

Answer 21

Both Sz and bipolar disorder involve positive symptoms like delusions and negative symptoms like avolition
This calls into question diagnosis - with ICD a patient might be diagnosed as a Sz but under DSM may be diagnosed as bipolar. Some argue they are the same condition

Question 22

What is the gender bias in diagnosis?

Answer 22

Longenecker reviewed prevalence of Sz and concluded since the 1980’s men have been diagnosed with Sz more often than women.
Men may be more genetically vulnerable to developing Sz
Female patients function better than men as they are more likely to work and have steady family relationships (cotton et al)
This may explain why some women have not been diagnosed as their ability to function may bias practitioners into a diagnosis - this may be impacted bu their ability to function socially

Question 23

What is the cultural bias in diagnosis?

Answer 23

African Americans and English Afro-Caribbean’s are several times more likely than white people to be diagnosed. As diagnosis is Africa and West Indies is not particularly high suggesting no genetic component. Instead it seems to be cultural bias

Question 24

What is the problem with differences in culture?

Answer 24

Positive symptoms such as hearing voices may well be acceptable in African cultures because of cultural belief of hearing ancestors - when reported to a psychiatrist of a different cultural background this may appear odd and thus lead to diagnosis
Escobar pointed out that overwhelmingly white psychiatrists may tend to over-interpret symptoms and trust the dishonesty of black people during diagnosis