Classification and Diagnosis

Question 1

What is SZ?

Answer 1

• A serious and very complex mental health disorder suffered by 1% of population.
• More commonly diagnosed in men than women, commonly diagnosed in cities than the countryside and WC rather than MC people.
• The symptoms of SZ can interfere severely with everyday tasks, so that many sufferers end up homeless or hospitalised.

Question 2

Classification of SZ.

Answer 2

2 main systems for the classification of mental disorders:
- ICD-10
- DSM-5
These differ slightly in their classification of SZ e.g. the ICD-10 recognises sub-types of SZ, whereas the new version of the DSM-5 does not.

Question 3

ICD-10: Subtypes of SZ.

Answer 3

• Catatonic SZ: the main feature is almost total immobility for hours at a time, with the patient simply staring blankly into space.
• Paranoid SZ: this type involves delusions of persecution.
• Hebephrenic SZ: this type involves great disorganisation of behaviour including delusions, hallucinations, incoherent speech and large mood swings.

Question 4

Types of SZ

Answer 4

Clinicians refer to two types of SZ:
- Type 1 - acute - positive symptoms (acute = rapid onset).
- Type 2 = chronic - negative symptoms (chronic = long-term state).

Question 5

What are positive symptoms?

Answer 5

Positive symptoms are defined as additional experiences beyond those of ordinary experiences. Individuals with positive symptoms tend to respond well to medication (drug therapy).

Question 6

Positive symptoms - 1. Hallucinations.

Answer 6

• These are unusual sensory experiences.
• Some hallucinations are related to the environment whereas some have no relationship to what the sense are picking up in the environment.
• Hallucinations can be experienced in relation to any of the five senses.
• e.g. seeing distorted facial expressions, seeing people or animals who aren’t there or hearing voices.

Question 7

Positive symptoms - 2. Delusions.

Answer 7

• Also known as paranoia - irrational beliefs.
• Can involve delusions about who you are, persecution and that parts of their body are under control.
• Delusions can lead to aggression but actually sufferers are more likely to be victims of violence.
• e.g. believing you are Jesus or another political or religious figure.

Question 8

What are negative symptoms?

Answer 8

Negative symptoms involve the loss of usual abilities and experiences.

Question 9

Negative symptoms - 1. Avolition.

Answer 9

• Inability to make decision (sometimes called apathy).
• Finding it difficult to begin or keep up with goal orientated activity.
• Lack of motivation.
• e.g. poor hygiene and grooming, lack of energy.

Question 10

Negative symptoms - 2. Speech poverty/speech disorganisation.

Answer 10

ICD-10: Speech poverty - reduction in the amount and quality of speech e.g. a delay in the sufferer’s verbal response in conversation (classified as negative symptom).
DSM-5: Speech disorganisation e.g. speech becomes incoherent or the speaker changes topic mid-sentence (classified as positive symptom).

Question 11

How classification system for SZ is reliable?

Answer 11

In terms of SZ, a classification system is reliable if 2 or more clinicians produce the same diagnosis across time and cultures.
There needs to be stable agreement over time when no symptoms change. If psychiatrists cannot agree on what constitutes SZ, then it becomes difficult to establish trust in the classification system.

Question 12

How classification system for SZ is valid?

Answer 12

In terms of SZ, the validity of classification system is judged by the extent to which SZ is found to be a unique syndrome with characteristics, signs and symptoms.

Question 13

Research into reliability of SZ: Cheniaux et al (2009)

Answer 13

• Two psychiatrists independently diagnosed 100 patients using both the DSM and ICD criteria.
• Inter-rater reliability was poor, with one psychiatrists diagnosing 26 people with SZ according to the DSM and 44 according to the ICD, and the other psychiatrist diagnosing 13 with the DSM and 24 with the ICD.
• This can be used as a limitation of SZ.

Question 14

Research into validity of SZ: Cheniaux et al (2009)

Answer 14

• In their study, it is much more likely to diagnose SZ using the ICD than the DSM.
• This suggests that SZ is either over-diagnosed in ICD or under-diagnosed in DSM. Either way this poor validity is an issue for the classification of SZ.

Question 15

Limitation of classification and diagnosis - the issue of co-morbidity.

Answer 15

P: A limitation of the validity of the classification and diagnosis of schizophrenia is comorbidity.
E: Comorbidity is the phenomenon that two or more conditions occur together. Buckley et al (2009) concluded that around half the patients with schizophrenia also have a diagnosis of depression
(50%) or substance abuse (47%).
L:This questions the validity of the accuracy of diagnosis.

Question 16

Limitation of classification and diagnosis - issue of gender bias.

Answer 16

P:Another limitation is the issue of gender bias in the diagnosis of schizophrenia.
E: Since the 1980s men have been diagnosed with SZ more than women. However, Cotton et al (2009) argue that women appear to function better than men with the condition. This high functioning may explain why women have not been diagnosed as frequently as
men.
L: This suggests that differences between males and females are being exaggerated (alpha bias).

Question 17

Limitation of classification and diagnosis - issue of culture bias.

Answer 17

P: A further limitation is the issue of culture bias in the diagnosis and classification of schizophrenia.
E: African Americans and English people of Afro-Caribbean origin are several times more likely than white people to be diagnosed with
SZ. One issue is that positive symptoms such as hearing voices are more acceptable in African cultures and thus people are more likely to acknowledge these experiences.
L:This suggests possible ethnocentrism, where western cultural norms are considered correct.

Question 18

Limitation of classification and diagnosis - issue of symptom overlap.

Answer 18

P: A final limitation in the diagnosis of schizophrenia is possible symptom overlap.
E: For example, both SZ and bipolar depression disorder involve positive symptoms such as delusions and negative symptoms such
as avolition. Under the ICD a patient would be diagnosed with SZ, whereas the same patient may receive a diagnosis of bipolar
disorder under the DSM.
L: It has been argued that schizophrenia and bipolar may not be two different conditions, but one.