Schizophrenia: Classification And Diagnosis

Question 1

What are the positive symptoms of Sz?

Answer 1

Positive experiences are additional experiences beyond those of ordinary existence
—> delusions
—> hallucinations

Question 2

What are delusions?

Answer 2

• an unshakeable belief in something that is very unlikely, bizarre and obviously untrue.
  —> e.g. paranoid delusions, belief that someone/something is deliberately trying to hurt, manipulate or even kill them
• another common delusion is grandeur, where individual believes that they have some imaginary power or authority - e.g. thinking they are on a mission from god or a secret agent

Question 3

What are hallucinations?

Answer 3

Auditory/visual - usually take the form of hearing voices that are not there. These voices are normally critical and unfriendly
Some people may also see, smell, taste and feel things that are not there (e.g. bugs crawling on them)

Question 4

What is catatonic or abnormal motor behaviour?

Answer 4

• where an individual behaves in a way that seems inappropriate or strange to norms of society
• catatonia involves having decreased reactivity to your environment

Question 5

What are disorganised thoughts and speech?

Answer 5

• individual speaks in ways that are completely incomprehendable
• e.g. sentences might not make sense, or topic of convo changes with little or no connection between sentences

Question 6

What are negative symptoms?

Answer 6

They are a loss of normal functions
- speech poverty (alogia)
- avolition

Question 7

What is speech poverty (alogia)?

Answer 7

decrease in verbal output or verbal expressiveness, alogia can make it nearly impossible to communicate your thoughts and carry on a convo
—> e.g. may answer with just a ‘yes’ or ‘no’ when responding or experience delays in getting the words out

Question 8

What is avolition?

Answer 8

• lack of motivation to follow through any plans and neglect household chores (e.g. washing dishes or cleaning)
• this can also include poor hygiene, lack of persistence in education , lack of work, lack of energy or not hanging out with friends or family

Question 9

What are some other negative symptoms?

Answer 9

• a lack of emotions —> voice become dull and monotonous and face takes a constant blank appearance
• inability to enjoy things they used to
• social withdrawal - can become reluctant to speak to people

Question 10

What is the DSM classification?

Answer 10

WHOs international classification of diseases.
- includes all medical disorders
- used in Europe
- focusses on the use of subtypes to classify Sz
—> patients need only 2 negative symptoms present

Question 11

What is the ICD classification?

Answer 11

APAs Diagnostic and Statistical Manual of mental disorders
- only includes mental disorders
- used in USA and Australia
- latest version has removed subtypes
—> patients must present at least one positive symptom and one other symptom

Question 12

Why is reliability important for Sz?

Answer 12

Reliability refers to the consistency of a measuring instrument, such as a questionnaire or scale.
Can be measured by:
- inter-rater - 2 independent investigators give the same diagnosis
- test-retest - tests deliver the same results over time

Question 13

What are the differences between the classifications?

Answer 13

ICD system appears to offer some advantage over the DSM:
- symptoms only need to be present for one month as opposed to six (DSM), so sufferers don’t have so much time where they might be at risk to themselves and others
- also only have to live without help for one month before receiving diagnosis and therefore appropriate treatment

Question 14

How is reliability affected by the differences in subtypes?

Answer 14

• ICD and DSM do not entirely agree on the number of subtypes of Sz, with the ICD suggesting 7 different subtypes and the DSM has got rid of subtypes (has 5)
• the reliability here is questioned as a sufferer could be diagnosed as just having Sz according to the DSM and a different subtype according to the ICD —> could cause incorrect treatment?

Question 15

What did Beck find about Inter-rater reliability?

Answer 15

Found the agreement on diagnosis for 153 patients (where each was assessed by 2 psychiatrists from a group of 4) was only 54%. This was often due to vague criteria for diagnosis and inconsistencies in techniques to gather data

Question 16

What did Whaley find about the inter-rater reliabilities?

Answer 16

Found inter rater reliability correlations in the diagnosis of Sz as low as 0.11 (0.8 is acceptable)

Question 17

What did Cheniaux find about reliability of the classifications?

Answer 17

Had 2 psychiatrists independently diagnose 100 people using both DSM and ICD criteria. 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
—> incorrect diagnosis - the result of problems with defining Sz, e.g. if you cannot classify Sz how can you diagnose it?

Question 18

How is Validity a problem with the classifications of Sz?

Answer 18

Validity refers to the extent that a diagnosis represents something that is real and distinct from other disorders and the extent that a classification system such as ICD or DSM measure what it claims to measure.
- reliability and validity are linked because if scientists cannot agree who has Sz (low reliability) then questions of what it actually is (validity) become essentially meaningless

Question 19

What is Criterion Validity?

Answer 19

• one standard way to assess validity of a diagnosis - do different systems arrive at the same diagnosis for the same person?
• Cheniaux study suggests that Sz is either over-diagnosed in ICD or under-diagnosed in DSM

Question 20

What is Comorbidity and how is it a validity problem?

Answer 20

• ## comorbidity is the phenomenon that 2 or more conditions occur together. If this happens a lot of the time, it calls into question the validity of their diagnosis and classification as they might actually be a single condition

Question 21

What did Buckley find about comorbidity?

Answer 21

• around half of people with a diagnosis of Sz also have a diagnosis of depression (50%), or substance abuse (47%). PTSD also occurred in 29% of cases and OCD in 23%.
  —> in terms of diagnosis with Sz, if half of those diagnosed with Sz are also diagnosed with depression, maybe we are bad at telling the difference between the 2 conditions
  —> for classification, if very severe depression looks like Sz and vice versa, then they might be better seen as a single condition.
• this confusing picture is a weakness of diagnosis and classification

Question 22

How is symptom overlap a problem for the validity of classification and diagnosis of Sz?

Answer 22

• theres a considerable overlap between the symptoms of Sz and other conditions
• e.g. both sz and bipolar involve positive symptoms like delusions and negative symptoms like avolition
• under ICD someone might be diagnosed with Sz, however many of the same individuals would receive diagnosis of bipolar according to DSM criteria.
  —> calls into question the validity of classification and diagnosis of Sz and even suggests that Sz and bipolar may not be 2 different conditions, but one

Question 23

How is the DSM culturally biased?

Answer 23

Created by Americans for Americans
- behaviour in one culture may not be regarded as a Sz symptom, but according to the DSM it is -e.g. hearing voices in some cultures is considered to be a message and regarded an honour
—> incorrect diagnosis

Question 24

What are the cultural variations for Sz?

Answer 24

• African Americans and English people of Afro-Caribbean origin are several times more likely than white people to be diagnosed with Sz
• given that rates in Africa and the West Indies are not particularly high, this is almost certainly not due to genetic vulnerability. Instead, diagnosis seems to be beset with issues of culture bias
• may be several factors that work here. One issue is that positive symptoms such as hearing voices may be more acceptable in African cultures because of cultural beliefs in communication with ancestors, and thus people are more ready to acknowledge such experiences
• when reported to a psychiatrist from a different cultural tradition these experiences are likely to be seen as bizarre and irrational

Question 25

What did Escobar find about cultural variations?

Answer 25

Pointed out that (overwhelmingly white) psychiatrists may tend to over-interpret symptoms and distrust the honesty of Afro-Caribbeans during diagnosis

Question 26

What did Davison and Neale find about cultural relativism?

Answer 26

In Asian cultures, a person experiencing some emotional turmoil is praised and rewarded if they show no expression of their emotions
- in certain Arabic cultures however, the outsourcing of public emotion is understood and often encouraged
- without this knowledge, an individual displaying overt emotional behaviour may be regarded as abnormal when in fact it is not

Question 27

What’s some more AO3 for cultural relativism?

Answer 27

• clinicians could misinterpret cultural differences in behaviour and expression as symptoms. Doctors don’t understand Black cultures and misdiagnose Sz, e.g. some Caribbean cultures believe you should talk to relatives/friends after they have died
• psychiatrists in Pakistan, China and India - think that the west place too much emphasis on separation of mind and body

Question 28

How is the ICD more universal?

Answer 28

• it is less culturally bias - can be applied to more diverse cultures as the WHO are made up of 193 countries and therefore various cultures are represented

Question 29

What did Longenecker find about gender bias in Sz classification and diagnosis?

Answer 29

He reviewed studies of the prevalence of Sz and concluded that since the 1980s, men have been diagnosed with Sz more often than women (prior to this there appears to be no difference)
- this may simply be because men are more genetically vulnerable than women

Question 30

What did Cotton find about gender bias in classification and diagnosis of Sz?

Answer 30

It appears women typically function better than men, being more likely to work and have good family relations
- this may explain why some women have not been diagnosed with Sz where men with similar symptoms might have been - their better interpersonal functioning may bias practitioners to under-diagnose Sz, either because symptoms are masked or because the quality of functioning makes the case seem to mild to warrant a diagnosis