Describe and evaluate diagnosis and classification of SZ (16 marks)
A01: • Schizophrenia is a severe mental disorder where contact with reality and insight
are impaired.
• According to the medical approach in order to diagnose a specific disorder we
need to distinguish one disorder from another. We do this by identifying clusters
of symptoms that occur together and classifying this as one disorder.
• The 2 major systems for classification of mental disorders are ICD-10 and DSM-
5.These slightly differ in their classification for SZ.
• DSM-5: 1 of the positive symptoms must be present for diagnosis
• ICD: 2 or more negative symptoms
• Positive symptoms are atypical symptoms experienced in addition to normal ex-
periences.
- Hallucinations are unusual sensory experiences. Some hallucinations are related
to events in the environment whereas others bear no relationship to what senses
are picking up from the environment eg. voices heard either talking to or com-
menting on a person. Hallucinations can be experienced in relation to any sense.
- Delusions are also known as paranoia, delusions are irrational beliefs. Common
delusions involve being an important historical, political or religious figure, such
as Jesus. Another class of delusions involves the body: a person may believe
they are under external control.
• Negative symptoms are atypical experiences that represent the loss of usual ex-
perience such as loss of clear thinking or loss of normal motivation.
- Speech poverty: SZ is characterised by changes in patterns of speech. Speech
poverty is seen as a negative symptom as emphasis is on reduction in the
amount of and quality of speech. This is sometimes accompanied by a delay in
persons verbal responses during conversation. Speech disorganisation in which
speech becomes incoherent or speaker changes topic mid sentence.
- Avolition: described as finding it difficult to begin or keep up with goal directed
activity. People with SZ often have sharply reduced motivation to carry out a
range of activities . Andreasen identified 3 signs of avolition: poor hygiene, lack
of persistence in work or education and lack of energy.
A03: • STRENGTH- One strength of diagnosis of SZ is its reliability. Reliability
means consistency. A psychiatric disorder is said to be reliable when different di-
agnosing clinicians reach the same diagnosis for the same individual (inter- rater
reliability) and on 2 occasions (test-retest reliability). Osario reported excellent
reliability for diagnosis of SZ in 180 individuals using DSM-5. Pairs of interviewers
achieved inter-rater reliability of +0.97 and test-retest reliability of +0.92.
• LIMITATION- Limitation of diagnosis of SZ is its validity. Cheniaux had 2
psychiatrists independently assess the same 100 clients using ICD-10 and DSM-5
criteria. Found 68 were diagnosed with SZ under ICD system and 39 under DSM.
This suggests that SZ is over or under diagnosed according to the diagnostic sys-
tem. Suggests criterion validity is low.
• LIMITATION- Limitation of diagnosis is co-morbidity with other conditions.
SZ is commonly diagnosed with other conditions. For example, 1 review found
that about 1/2 diagnosed with SZ also had a diagnosis of depression or substance
abuse. This problem for classification because it means SZ may not exist as a dis-
tinct condition and is a problem for diagnosis as some people diagnosed with SZ
may have unusual cases of conditions like depression.
• LIMITATION- The existence of cultural bias. Some symptoms of SZ, particu-
larly hearing voices have different meanings in different cultures. For example in
some Afro-caribbean societies voices may be attributed to communications from
ancestors. Afro-carribeans living in the UK are up to 10 times as likely to receive
diagnosis as white British people. Afro-carribean may be discriminated against by
culturally biased diagnostic system.
,
A01: • Schizophrenia is a severe mental disorder where contact with reality and insight
are impaired.
• According to the medical approach in order to diagnose a specific disorder we
need to distinguish one disorder from another. We do this by identifying clusters
of symptoms that occur together and classifying this as one disorder.
• The 2 major systems for classification of mental disorders are ICD-10 and DSM-
5.These slightly differ in their classification for SZ.
• DSM-5: 1 of the positive symptoms must be present for diagnosis
• ICD: 2 or more negative symptoms
• Positive symptoms are atypical symptoms experienced in addition to normal ex-
periences.
- Hallucinations are unusual sensory experiences. Some hallucinations are related
to events in the environment whereas others bear no relationship to what senses
are picking up from the environment eg. voices heard either talking to or com-
menting on a person. Hallucinations can be experienced in relation to any sense.
- Delusions are also known as paranoia, delusions are irrational beliefs. Common
delusions involve being an important historical, political or religious figure, such
as Jesus. Another class of delusions involves the body: a person may believe
they are under external control.
• Negative symptoms are atypical experiences that represent the loss of usual ex-
perience such as loss of clear thinking or loss of normal motivation.
- Speech poverty: SZ is characterised by changes in patterns of speech. Speech
poverty is seen as a negative symptom as emphasis is on reduction in the
amount of and quality of speech. This is sometimes accompanied by a delay in
persons verbal responses during conversation. Speech disorganisation in which
speech becomes incoherent or speaker changes topic mid sentence.
- Avolition: described as finding it difficult to begin or keep up with goal directed
activity. People with SZ often have sharply reduced motivation to carry out a
range of activities . Andreasen identified 3 signs of avolition: poor hygiene, lack
of persistence in work or education and lack of energy.
A03: • STRENGTH- One strength of diagnosis of SZ is its reliability. Reliability
means consistency. A psychiatric disorder is said to be reliable when different di-
agnosing clinicians reach the same diagnosis for the same individual (inter- rater
reliability) and on 2 occasions (test-retest reliability). Osario reported excellent
reliability for diagnosis of SZ in 180 individuals using DSM-5. Pairs of interviewers
achieved inter-rater reliability of +0.97 and test-retest reliability of +0.92.
• LIMITATION- Limitation of diagnosis of SZ is its validity. Cheniaux had 2
psychiatrists independently assess the same 100 clients using ICD-10 and DSM-5
criteria. Found 68 were diagnosed with SZ under ICD system and 39 under DSM.
This suggests that SZ is over or under diagnosed according to the diagnostic sys-
tem. Suggests criterion validity is low.
• LIMITATION- Limitation of diagnosis is co-morbidity with other conditions.
SZ is commonly diagnosed with other conditions. For example, 1 review found
that about 1/2 diagnosed with SZ also had a diagnosis of depression or substance
abuse. This problem for classification because it means SZ may not exist as a dis-
tinct condition and is a problem for diagnosis as some people diagnosed with SZ
may have unusual cases of conditions like depression.
• LIMITATION- The existence of cultural bias. Some symptoms of SZ, particu-
larly hearing voices have different meanings in different cultures. For example in
some Afro-caribbean societies voices may be attributed to communications from
ancestors. Afro-carribeans living in the UK are up to 10 times as likely to receive
diagnosis as white British people. Afro-carribean may be discriminated against by
culturally biased diagnostic system.
,
