Schizophrenia
Schizophrenia (Sz):
● Sz is the most chronic and debilitating of the mental disorders.
● Characterized by periods of loss of touch with reality (psychosis).
● 1% of the population suffer from schizophrenia.
● The prevalence rates are higher for men than women and the onset age is earlier for
men.
● Every case of SZ is different. 7-15% have only one episode. However it usually
involves repeated psychotic episodes and a chronic, downhill course over years.
● Interferes severely with everyday tasks with, approximately 4.9% die via suicide.
Classification of Schizophrenia:
What is classification:
The process of organising symptoms into categories based on which symptoms frequently
occur together.
Who Diagnoses Schizophrenia:
● The DSM (Diagnostic and Statistical Manual of Mental Disorders) is a huge book
produced by the American Psychiatric Association.
● It contains a list of symptoms for each disorder and guidelines for clinicians who
make diagnoses.
● The DSM is more commonly used to diagnose schizophrenia.
● The ICD (International Classification of Diseases) is produced by the World Health
● Organisation and includes both physical and mental illnesses. It is used more
commonly in Europe.
How do you diagnose Schizophrenia:
● There are many clinical characteristics of Sz and they are split into positive and
negative.
● Positive symptoms are those that appear to reflect an excess or distortion of normal
functions. They add something to the person.
● Negative symptoms are those that appear to reflect a reduction or absence of usual
mental functions which appear during periods of low (or absent) positive symptoms.
They take away from the person.
● The DSM-5 states that an individual must show two or more of the following negative
symptoms for at least one month alongside reduced social functioning:
○ Delusions
○ Hallucinations
○ Disorganized speech
○ Disorganized or catatonic behaviour.
● One of the symptoms must be positive either delusions, hallucinations or
disorganised speech.
● The ICD-10 states that to be diagnosed with Sz an individual must show one very
clear positive symptom or if less clear two or more symptoms (positive or negative)
during a period of one month or more.
● ICD-10 also recognises subtypes of Sz:
, ○ Paranoid Sz – powerful delusions and hallucinations with very few other
symptoms.
○ Catatonic Sz- disturbance in movement.
Positive symptoms of schizophrenia:
● False beliefs that seem real to the person with SZ, but aren’t.
● Paranoid delusions: Believe someone is out to get them and worried about safety.
● Grandiose (pretentiously thinking you are impressive or magnificent in appearance of
style) delusions: Involves fantastical beliefs that you are famous, wealthy, or
otherwise very powerful. E.g. Some patients believe they are God or a famous rock
star.
● Delusions of control: The person may believe they are under the control of an alien
force that has invaded their body and mind. Feel like someone is controlling them or
has power over them.
● People with SZ often see bizarre and unreal perceptions of the environment. These
can either be:
○ Auditory – This usually involves hearing voices inside their head which tell
them to do certain things.
○ Visual – Involves seeing lights, objects, or faces.
○ Tactile – Hallucinations about feeling things such as bugs crawling on skin
etc.
Negative symptoms of schizophrenia:
● Poverty of speech is characterised by a change in patterns of speech.
● It is characterised by the lessening of speech fluency which is thought to reflect the
slowing of or blocked thoughts.
● Marked by a reduction in speech production.
● Avolition is a psychological state characterised by general lack of drive, or motivation
to pursue meaningful goals. For example sitting in the house for hours every day,
doing nothing, not wanting to get a job or socialise etc.
● Not wanting to do anything which would better yourself to meet your goals.
● Anderson identified three signs of avolition:
○ Poor hygiene and grooming.
○ Lack of persistence in work or education.
○ Lack of energy.
Reliability in diagnosis and classification of schizophrenia
The issue of giving a reliable diagnosis:
The problem lies with psychiatrists and clinicians needing to have a reliable way (e.g. DSM,
ICD) of diagnosing schizophrenia in patients. When considering the reliability of diagnosis
and classification it is focused on the level of agreement on the diagnosis of schizophrenia
by different psychiatrists across time and culture. The diagnosis of schizophrenia should
remain stable over time if there is no change in symptoms.
The way that the reliability of these measures can be assessed is by calculating their
inter-rater reliability. The extent to which two or more psychiatrists give the same diagnosis
for the same patients using the same diagnostic scale.
Problem 1:The DSM is too vague
, Early versions of the DSM were not very reliable due to the vague criteria within the DSM
that psychiatrists used to diagnose schizophrenia. For example, in one of the early versions
'bizarre' delusions was one of the criteria.
● Evaluation of problem 1:
This can be supported by research from Beck (1962) Reported that 4 experienced clinicians
each relying on DSM-I, independently inter- viewed 153 patients recently admitted to a
mental hospital. Only 54% of their diagnoses were in agreement.
This was often due to vague criteria for diagnosis and inconsistencies in techniques to
gather data.
Problem 1 expanded: Are newer versions still unreliable?
The publication of the DSM-II in 1980 was specifically designed to provide a more reliable
system for classifying psychiatric disorders. These updated versions of the DSM, the most
recent being the DSM-V which was released in 2013 include more detailed and
operationalised definitions and categories for diagnosing Sz.
Plus, psychiatrists now use standardised interview schedules when assessing patients.
Some research suggests that the increase in the operationalisation of the symptoms and
categories has improved the reliability of the DSM at diagnosing Sz. For example, fication
system. Soderberg et al (2005) reported a concordance rate of 81% when using the DSM
classification system.
● Evaluation of Problem 1: However not all research supports this view
To support this Carney (2013) reports that inter-rater reliability for schizophrenia using
DSM-V to diagnose is 0.46. Ivalvation
Problem 2: Cultural bias:
For a reliable classification and diagnosis of schizophrenia there should be consistency
across cultures. In other words the rates of diagnosis should be the same across all cultures
given that the risk of developing schizophrenia is 1% worldwide There is considerable
variation between cultures in the rates of diagnosis which further challenges the reliability of
diagnosing and classifying schizophrenia. For a reliable diagnosis we need to find a
consistent worldwide measure to classify and diagnose schizophrenia.
● Evaluation of problem 2, cultural bias:
There is research evidence to support cross- cultural differences in diagnosis. Copeland
(1971) gave 134 US and 194 UK psychiatrists a description of the patient. 69% of the US
psychiatrists gave a diagnosis of schizophrenia compared to 2% of the UK psychiatrists.
In addition to this Cochrane (1977) found the prevalence rate of schizophrenia in the west
indies and UK is 1%. However, Afro-Caribbean people living in Britain are 7 times more likely
to be diagnosed with schizophrenia.
Reliability in diagnosis and classification of schizophrenia:
A valid diagnosis refers to the extent that a diagnosis represents something that is real and
distinct from other disorders and the extent to which a classification system (DSM
and ICD) is measuring what it claims to measure (ie Sz.). When classifying and diagnosing
schizophrenia there are a number issues to be considered:
Schizophrenia (Sz):
● Sz is the most chronic and debilitating of the mental disorders.
● Characterized by periods of loss of touch with reality (psychosis).
● 1% of the population suffer from schizophrenia.
● The prevalence rates are higher for men than women and the onset age is earlier for
men.
● Every case of SZ is different. 7-15% have only one episode. However it usually
involves repeated psychotic episodes and a chronic, downhill course over years.
● Interferes severely with everyday tasks with, approximately 4.9% die via suicide.
Classification of Schizophrenia:
What is classification:
The process of organising symptoms into categories based on which symptoms frequently
occur together.
Who Diagnoses Schizophrenia:
● The DSM (Diagnostic and Statistical Manual of Mental Disorders) is a huge book
produced by the American Psychiatric Association.
● It contains a list of symptoms for each disorder and guidelines for clinicians who
make diagnoses.
● The DSM is more commonly used to diagnose schizophrenia.
● The ICD (International Classification of Diseases) is produced by the World Health
● Organisation and includes both physical and mental illnesses. It is used more
commonly in Europe.
How do you diagnose Schizophrenia:
● There are many clinical characteristics of Sz and they are split into positive and
negative.
● Positive symptoms are those that appear to reflect an excess or distortion of normal
functions. They add something to the person.
● Negative symptoms are those that appear to reflect a reduction or absence of usual
mental functions which appear during periods of low (or absent) positive symptoms.
They take away from the person.
● The DSM-5 states that an individual must show two or more of the following negative
symptoms for at least one month alongside reduced social functioning:
○ Delusions
○ Hallucinations
○ Disorganized speech
○ Disorganized or catatonic behaviour.
● One of the symptoms must be positive either delusions, hallucinations or
disorganised speech.
● The ICD-10 states that to be diagnosed with Sz an individual must show one very
clear positive symptom or if less clear two or more symptoms (positive or negative)
during a period of one month or more.
● ICD-10 also recognises subtypes of Sz:
, ○ Paranoid Sz – powerful delusions and hallucinations with very few other
symptoms.
○ Catatonic Sz- disturbance in movement.
Positive symptoms of schizophrenia:
● False beliefs that seem real to the person with SZ, but aren’t.
● Paranoid delusions: Believe someone is out to get them and worried about safety.
● Grandiose (pretentiously thinking you are impressive or magnificent in appearance of
style) delusions: Involves fantastical beliefs that you are famous, wealthy, or
otherwise very powerful. E.g. Some patients believe they are God or a famous rock
star.
● Delusions of control: The person may believe they are under the control of an alien
force that has invaded their body and mind. Feel like someone is controlling them or
has power over them.
● People with SZ often see bizarre and unreal perceptions of the environment. These
can either be:
○ Auditory – This usually involves hearing voices inside their head which tell
them to do certain things.
○ Visual – Involves seeing lights, objects, or faces.
○ Tactile – Hallucinations about feeling things such as bugs crawling on skin
etc.
Negative symptoms of schizophrenia:
● Poverty of speech is characterised by a change in patterns of speech.
● It is characterised by the lessening of speech fluency which is thought to reflect the
slowing of or blocked thoughts.
● Marked by a reduction in speech production.
● Avolition is a psychological state characterised by general lack of drive, or motivation
to pursue meaningful goals. For example sitting in the house for hours every day,
doing nothing, not wanting to get a job or socialise etc.
● Not wanting to do anything which would better yourself to meet your goals.
● Anderson identified three signs of avolition:
○ Poor hygiene and grooming.
○ Lack of persistence in work or education.
○ Lack of energy.
Reliability in diagnosis and classification of schizophrenia
The issue of giving a reliable diagnosis:
The problem lies with psychiatrists and clinicians needing to have a reliable way (e.g. DSM,
ICD) of diagnosing schizophrenia in patients. When considering the reliability of diagnosis
and classification it is focused on the level of agreement on the diagnosis of schizophrenia
by different psychiatrists across time and culture. The diagnosis of schizophrenia should
remain stable over time if there is no change in symptoms.
The way that the reliability of these measures can be assessed is by calculating their
inter-rater reliability. The extent to which two or more psychiatrists give the same diagnosis
for the same patients using the same diagnostic scale.
Problem 1:The DSM is too vague
, Early versions of the DSM were not very reliable due to the vague criteria within the DSM
that psychiatrists used to diagnose schizophrenia. For example, in one of the early versions
'bizarre' delusions was one of the criteria.
● Evaluation of problem 1:
This can be supported by research from Beck (1962) Reported that 4 experienced clinicians
each relying on DSM-I, independently inter- viewed 153 patients recently admitted to a
mental hospital. Only 54% of their diagnoses were in agreement.
This was often due to vague criteria for diagnosis and inconsistencies in techniques to
gather data.
Problem 1 expanded: Are newer versions still unreliable?
The publication of the DSM-II in 1980 was specifically designed to provide a more reliable
system for classifying psychiatric disorders. These updated versions of the DSM, the most
recent being the DSM-V which was released in 2013 include more detailed and
operationalised definitions and categories for diagnosing Sz.
Plus, psychiatrists now use standardised interview schedules when assessing patients.
Some research suggests that the increase in the operationalisation of the symptoms and
categories has improved the reliability of the DSM at diagnosing Sz. For example, fication
system. Soderberg et al (2005) reported a concordance rate of 81% when using the DSM
classification system.
● Evaluation of Problem 1: However not all research supports this view
To support this Carney (2013) reports that inter-rater reliability for schizophrenia using
DSM-V to diagnose is 0.46. Ivalvation
Problem 2: Cultural bias:
For a reliable classification and diagnosis of schizophrenia there should be consistency
across cultures. In other words the rates of diagnosis should be the same across all cultures
given that the risk of developing schizophrenia is 1% worldwide There is considerable
variation between cultures in the rates of diagnosis which further challenges the reliability of
diagnosing and classifying schizophrenia. For a reliable diagnosis we need to find a
consistent worldwide measure to classify and diagnose schizophrenia.
● Evaluation of problem 2, cultural bias:
There is research evidence to support cross- cultural differences in diagnosis. Copeland
(1971) gave 134 US and 194 UK psychiatrists a description of the patient. 69% of the US
psychiatrists gave a diagnosis of schizophrenia compared to 2% of the UK psychiatrists.
In addition to this Cochrane (1977) found the prevalence rate of schizophrenia in the west
indies and UK is 1%. However, Afro-Caribbean people living in Britain are 7 times more likely
to be diagnosed with schizophrenia.
Reliability in diagnosis and classification of schizophrenia:
A valid diagnosis refers to the extent that a diagnosis represents something that is real and
distinct from other disorders and the extent to which a classification system (DSM
and ICD) is measuring what it claims to measure (ie Sz.). When classifying and diagnosing
schizophrenia there are a number issues to be considered:
