Classification of schizophrenia

Question 1

What is schizophrenia?

Answer 1

A severe mental illness where contact with reality and insight are impaired, an example of psychosis.

Question 2

What percentage of people in the world suffer from schizophrenia?

Answer 2

1%.

Question 3

Define classification of a mental disorder.

Answer 3

The process of organising symptoms into categories based on which symptoms cluster together in sufferers.

Question 4

What are the 2 major systems used in the classification of a mental disorder?

Answer 4

ICD-10 (World Health Organisation)

DSM-5 (American)

Question 5

What are positive symptoms of schizophrenia?

Answer 5

Atypical symptoms experienced in ADDITION to normal experiences.

Question 6

Name 2 positive symptoms of schizophrenia.

Answer 6

Delusions

Hallucinations

Question 7

What are hallucinations?

Answer 7

Sensory experiences of stimuli that have either no basis in reality or are distorted perceptions of things that are there.
Can be:
- auditory
- tactile
- olfactory
- visual

Question 8

What are delusions?

Answer 8

They involve beliefs that have no basis in reality.

E.G. paranoia, delusions of grandeur

Question 9

What are negative symptoms of schizophrenia?

Answer 9

Atypical experiences that represent the loss of a usual experience, e.g. ‘normal’ levels of motivation.

Question 10

Name 3 negative symptoms.

Answer 10

Avolition
Alogia (speech poverty)
Affective flattening

Question 11

What is avolition?

Answer 11

Loss of motivation to carry out tasks and results in lowered activity levels.

Question 12

What is alogia?

Answer 12

Alogia is speech poverty and involves the reduced frequency and quality of speech.

Question 13

What is affective flattening?

Answer 13

A los of intensity in the demonstration of emotion.

Question 14

State 6 criticisms of the diagnosis and classification of schizophrenia.

Answer 14

Reliability.
Validity.
Co-morbidity.
Symptom overlap.
Gender bias.
Culture bias.

Question 15

Explain the criticism of the issue of reliability when diagnosing and classifying schizophrenia.

Answer 15

• Reliability = consistency.
• An important measure of reliability is inter-rater reliability, the extent to which different assessors agree on their assessment.
• Cheniaux et al. had 2 psychiatrists independently diagnose 100 patients using both DSM and ICD criteria; inter-rater reliability was poor. One psychiatrist diagnosed 26 with DSM and 44 with ICD, the other diagnosed 13 with DSM and 24 with ICD.

Question 16

Explain the criticism of the issue of validity when diagnosing and classifying schizophrenia.

Answer 16

Validity is the extent to which we are measuring what we intended to measure.
From Cheniaux’s study we can conclude that schizophrenia is much more likely to be diagnosed when using the ICD than the DSM.
This suggests that schizophrenia is either over diagnosed by ICD or under diagnosed by the DSM - either way it shows poor validity and a weakness in diagnosis.

Question 17

Explain the criticism of the issue of co-morbidity when diagnosing and classifying schizophrenia.

Answer 17

Co-morbidity is the occurrence of 2 illnesses or conditions together. E.G. schizophrenia and a personality disorder.
When 2 conditions are frequently diagnosed together it calls into question the validity of classifying the 2 disorders separately.
Buckley et al. concluded that 50% of people diagnosed with schizophrenia were also diagnosed with depression, and 47% with substance abuse. PTSD also occurred in 29% of the cases, and OCD in 23%.

Question 18

Explain the criticism of the issue of symptom overlap when diagnosing and classifying schizophrenia.

Answer 18

There is a considerable overlap between schizophrenia and other conditions, and occurs when 2 or more conditions share symptoms.
E.G. both schizophrenia and bipolar disorder involve positive symptoms like delusions and negative symptoms like avolition.
Under ICD a patient might be diagnosed with schizophrenia but using the DSM may be diagnosed with bipolar.

Question 19

Explain the criticism of the issue of gender bias when diagnosing and classifying schizophrenia.

Answer 19

Longenecker et al. found that since the 1980’s more men have been diagnosed with schizophrenia than women. - could be due to a genetic vulnerability.
BUT female patients typically function better than men, being more likely to work and have good family relationships. This high functioning may explain why women are less likely to be diagnosed as symptoms are masked by good interpersonal functioning.

Question 20

Explain the criticism of the issue of cultural bias when diagnosing and classifying schizophrenia.

Answer 20

African Americans and English people of Afro-carribean origin are several times more likely to be diagnosed with schizophrenia - due to rates in Africa and West Indies are considerably low this shows that this is not due to a genetic vulnerability. 
Positive symptoms (such as hearing voices) may be more acceptable in African cultures due to the belief in communication with ancestors, and thus people are more ready to acknowledge such experiences.
Escobar et al. pointed out that overwhelmingly white psychiatrists may tend to over-interpret symptoms and distrust the honesty of black people during diagnosis.