Diagnosis And Classification Of SZ

Question 1

What is Schizophrenia?

Answer 1

A psychosis - a severe mental disorder involving major disturbances in thought, emotion and behaviour.

Question 2

How common is Schizophrenia in the population?

Answer 2

1%

Question 3

Who is diagnosed more? Males or females?

Answer 3

Males

Question 4

What is the average age of onset?

Answer 4

15-34

Question 5

What % of SZ patients commit suicide?

Answer 5

10%

Question 6

What are the two types of symptom?

Answer 6

Positive and negative symptoms

Question 7

List 3 positive symptoms

Answer 7

Hallucinations, delusions, agitation

Question 8

List 3 negative symptoms

Answer 8

Flat effect, avolition, alogia

Question 9

What are the 5 subtypes of SZ?

Answer 9

• Paranoid
• Disorganised
• Catatonic
• Undifferentiated
• Residual

Question 10

What are the two manuals used to diagnose SZ?

Answer 10

DSM-5 in the U.S. and the ICD-10 in Europe.

Question 11

According to the DSM what characteristics are needed for diagnosis of SZ?

Answer 11

Criterion A
Two or more of the following:
• Delusions
• Hallucinations
• Disorganised speech
• Grossly disorganised or catatonic behaviour
• Negative symptoms

Criterion B - Social/occupational dysfunction
One or more major areas of functioning such as work, interpersonal relationships or self-care must be markedly below the level achieved prior to onset for a significant portion of time.

Criterion C - Duration
Continuous signs of disturbance for at least 6 months. Must be at least 1 month of symptoms from criterion A

Question 12

What is required for diagnosis to be reliable?

Answer 12

Test-retest reliability - a mental health professional gives the same diagnosis for the same symptoms at different points in time.
Inter-rater reliability - different mental health professionals must arrive at the same diagnosis for the same patient.

Question 13

What happened in Rosenhan’s study?

Answer 13

8 ‘pseudo-patients’ who were psychologically healthy made appointments at different hospitals in the USA. At the appointment they complained of hearing an unfamiliar voice often using the words ‘thud’, ‘hollow’, and ‘empty’. 7 out of 8 were diagnosed with SZ and were admitted to hospital. From then on they acted normally and it took between 7 and 52 days to be released. Hospital staff throughout interpreted normal behaviour as normal.

Question 14

What conclusion about the reliability of SZ diagnosis did Rosenhan give?

Answer 14

The diagnosis is unreliable and can result in misdiagnosis.

Question 15

What did Read’s research into test-retest reliability find?

Answer 15

A 38% concordance rate, making it only 38% likely a SZ patient would be diagnosed with SZ again sometime after the original diagnosis. This shows there’s a high level of misdiagnosis

Question 16

What did Cheniaux find about inter-rater reliability?

Answer 16

That there was poor inter-rater reliability, with one psychiatrist diagnosing 70/100 patients with SZ whilst another diagnosed only 37 out of the same 100 patients.

Question 17

What does validity mean in terms of diagnosis and classification?

Answer 17

Diagnosis -refers to the extent to which Schizophrenia is a unique disorder with signs and symptoms that are separate from others.

Classification - refers to the extent to which classification systems such as the DSM and the ICD measure what they claim to.

Question 18

What is the problem when diagnosing SZ when it comes to predictive validity?

Answer 18

There’s no evidence that people with SZ will share the same outcomes. Prognosis varies and so the diagnosis has little predictive validity.

Question 19

How is gender bias a problem in diagnosing SZ?

Answer 19

Males have been diagnosed more often than females and female schizophrenics tend to function better than males. This explains possibly why males are diagnosed more, leading to more expectation of a male to be suffering from SZ than a female.

Question 20

What does co-morbidity mean and how does it affect disgnosis?

Answer 20

Refers to the occurrence of two or more conditions together. E.g. SZ and depression.
If conditions are frequently diagnosed together it calls into question the validity of classifying the 2 together as they may be one disorder.

Question 21

What did Buckley’s 2009 study find about co-morbidity and SZ? How does it pose a problem to classification and diagnosis?

Answer 21

50% of patients with SZ also had depression. 47% with substance abuse. 23% had OCD.
In terms of diagnosis it could show clinicians are bad at telling the difference between depression and SZ.

In terms of classification it might be better for SZ and severe depression to be classified as a single condition.

Question 22

Why is symptom overlap a problem for both classification and diagnosis?

Answer 22

Considerable overlap between symptoms of SZ and other disorders. Both SZ and BPD include positive symptoms (like hallucinations) and negative symptoms (like avolition). The ICD would diagnose a person as schizophrenic with these symptoms but the DSM would diagnose them with BPD. Calls into question validity of classification and the accuracy of diagnosis.

Question 23

How does culture have an impact on diagnosis?

Answer 23

African Americans and Europeans of Afro-caribbean origin as more likely to be diagnosed. However rates in Africa and the West Indies are not high, suggesting genetics don’t play a role.
This indicates culture bias because certain positive symptoms in African cultures are more acceptable. A psychiatrist may see these experiences as more bizarre as they are from a different culture. Or a psychiatrist over-interprets symptoms and distrusts the honesty of black people.