Schizophrenia
, LT1
Clinical Characteristics and Classification of Schizophrenia
Schizophrenia → a psychotic mental disorder characterised by major disturbances in thought, emotion and behaviour to such a degree that the person loses touch
with reality. Believe things that cannot be true (delusions) or hearing voices and seeing visions (hallucinations)
Classification of a mental disorder → process of organising symptoms into categories based on which symptoms cluster together
Diagnostic and statistical manual (DSM) The International Classification of Disease edition 10 (ICD-10)
- Published by American Psychiatric Association providing a criteria to - Diagnostic system used for all diseases - physical and mental
diagnose a mental health disorder - Free and public access
- DSM-V used to classify over 300 mental disorders based on symptoms - Split into 25 categories, mental and behavioural disorders are
and divided in 3 sections chapter V. F00-F99
- 1: intro on how the manual is organised, how it is changed from the - Clinician selects key words from a interview relating to symptoms
DSM-IV and how it is used e.g. hallucinations
- 2: gives a diagnostic criteria based around causes and symptoms of the - Looks up symptoms in an alphabetical index where symptoms
main mental health disorders e.g. SZ spectrum can be considered further and a subcategory is chosen
- 3: look at other assessment methods to aid diagnosis e.g. cultural - Two or more of the negative symptoms must be present
context
- One positive symptom must be present Positive symptoms Negative symptoms
Features of Schizophrenia (facts and stats) Hallucinations: Unusual sensory experiences Alogia: Poverty of speech - associated with
1. Affects 1% of the population (peak=25-30yrs, rare - false perceptions that don’t correspond reduction in quality and amt of speech. Few
at child) with reality by affecting senses. words, poor fluency reflective of blocked
2. No gender differences Auditory hallucinations = hear voices. thoughts/ delay of response
3. Different types; paranoid, disorganised, catatonic, Experience them as separate to them Avolition: social withdrawal/ apathy - no
residual and undifferentiated - different symptoms Visual hallucinations = events that aren’t longer interacts with family and friends and
4. Positive symptoms → refers to excesses of normal happening. struggling to keep up with goal orientated
behaviour e.g. hallucinations -> Atypical Delusions: Irrational beliefs that remain even activities ee.g. school/work
5. Negative symptoms → refer to normal behaviour when shown not true. Lack of energy and apathy → no motivation
that is missing e.g. social withdrawal -> Atypical Delusions of grandeur - person believes for daily chores = poor appearance and
6. Violence → 8% commit violent acts, more than they’re famous/wealthy and have religious or maintaining sense of self
general public but less than others with mental supernatural theme. Affective flattening: face is emotionless and
disorders Paranoid delusions - think someone is trying voice is dull with no rise and fall can include
7. Affect with everyday life and can lead to to kill them eye contact and body language
hospitalisation Disordered thinking: can’t think straight
, LT2
Reliability and validity in diagnosis and classification
RELIABILITY AND DIAGNOSIS OF SCHIZOPHRENIA VALIDITY AND DIAGNOSIS OF SCHIZOPHRENIA
- When the same set of symptoms would get the same diagnosis - If it correctly reflects and actual disorder which means the
from different psychiatrists across time and cultures symptoms of the patient match those considered to be present
- Reliable diagnosis = stable over time given no change in for that disorder
symptoms - Not valid = incorrect and does not have that illness
Can be measured in various ways: - Valid = operationalise the symptoms and behaviours that
1. Inter rater reliability → extent to which 2 more more make up a mental health disorder
clinicians agree on the same diagnosis Can be measured in various ways:
- A reliability score of 0.7 means that a patient judged as 1. Concurrent validity → two different diagnostic systems
having schizophrenia by one clinician has a 70% chance of agree about the symptoms of mental health disorders. If
being diagnosed with Sz by another = good reliability diagnosis using the DSM comes up with the same mental
- Tested between two clinicians = increase inter rater disorder as a diagnosis using the ICD, then it will have
reliability concurrent validity
2. Test retest reliability → a diagnosis is reliable if it is 2. Predictive validity → the extent to which results from a
consistent over two different time periods for the same diagnostic tool e.g. DSM can predict future behaviour. If it
patient using the same psychiatrist and the same diagnosis leads to a treatment and can be used to predict how that
tool treatment will work on the patient = has predictive validity
Issues affecting the classification and diagnosis of Sz
SYMPTOM OVERLAP:
- Symptoms of Sz overlaps with other disorders so different psychiatrists may diagnose a different disorder instead of Sz =
diagnosis is unreliable. Incorrect diagnosis could take place = not valid e.g. Sz and bipolar disorder involve +ve symptoms e.g.
delusions and -ve symptoms e.g. avolition = questions reliability and validity of classification and diagnosis
- Most people who are diagnosed have enough symptoms of other disorders that they could also receive at least one other diagnosis
= validity of Sz as a single disorder can be questioned
- Ketter (05)- misdiagnosis due to symptom overlap = years of delay in recieving relevant treatment, during which time suffering
and further degeneration can occur as well as high level of suicide. Highlights symptom overlap as having serious concequences
and economic implication for the healthcare system
, LT1
Clinical Characteristics and Classification of Schizophrenia
Schizophrenia → a psychotic mental disorder characterised by major disturbances in thought, emotion and behaviour to such a degree that the person loses touch
with reality. Believe things that cannot be true (delusions) or hearing voices and seeing visions (hallucinations)
Classification of a mental disorder → process of organising symptoms into categories based on which symptoms cluster together
Diagnostic and statistical manual (DSM) The International Classification of Disease edition 10 (ICD-10)
- Published by American Psychiatric Association providing a criteria to - Diagnostic system used for all diseases - physical and mental
diagnose a mental health disorder - Free and public access
- DSM-V used to classify over 300 mental disorders based on symptoms - Split into 25 categories, mental and behavioural disorders are
and divided in 3 sections chapter V. F00-F99
- 1: intro on how the manual is organised, how it is changed from the - Clinician selects key words from a interview relating to symptoms
DSM-IV and how it is used e.g. hallucinations
- 2: gives a diagnostic criteria based around causes and symptoms of the - Looks up symptoms in an alphabetical index where symptoms
main mental health disorders e.g. SZ spectrum can be considered further and a subcategory is chosen
- 3: look at other assessment methods to aid diagnosis e.g. cultural - Two or more of the negative symptoms must be present
context
- One positive symptom must be present Positive symptoms Negative symptoms
Features of Schizophrenia (facts and stats) Hallucinations: Unusual sensory experiences Alogia: Poverty of speech - associated with
1. Affects 1% of the population (peak=25-30yrs, rare - false perceptions that don’t correspond reduction in quality and amt of speech. Few
at child) with reality by affecting senses. words, poor fluency reflective of blocked
2. No gender differences Auditory hallucinations = hear voices. thoughts/ delay of response
3. Different types; paranoid, disorganised, catatonic, Experience them as separate to them Avolition: social withdrawal/ apathy - no
residual and undifferentiated - different symptoms Visual hallucinations = events that aren’t longer interacts with family and friends and
4. Positive symptoms → refers to excesses of normal happening. struggling to keep up with goal orientated
behaviour e.g. hallucinations -> Atypical Delusions: Irrational beliefs that remain even activities ee.g. school/work
5. Negative symptoms → refer to normal behaviour when shown not true. Lack of energy and apathy → no motivation
that is missing e.g. social withdrawal -> Atypical Delusions of grandeur - person believes for daily chores = poor appearance and
6. Violence → 8% commit violent acts, more than they’re famous/wealthy and have religious or maintaining sense of self
general public but less than others with mental supernatural theme. Affective flattening: face is emotionless and
disorders Paranoid delusions - think someone is trying voice is dull with no rise and fall can include
7. Affect with everyday life and can lead to to kill them eye contact and body language
hospitalisation Disordered thinking: can’t think straight
, LT2
Reliability and validity in diagnosis and classification
RELIABILITY AND DIAGNOSIS OF SCHIZOPHRENIA VALIDITY AND DIAGNOSIS OF SCHIZOPHRENIA
- When the same set of symptoms would get the same diagnosis - If it correctly reflects and actual disorder which means the
from different psychiatrists across time and cultures symptoms of the patient match those considered to be present
- Reliable diagnosis = stable over time given no change in for that disorder
symptoms - Not valid = incorrect and does not have that illness
Can be measured in various ways: - Valid = operationalise the symptoms and behaviours that
1. Inter rater reliability → extent to which 2 more more make up a mental health disorder
clinicians agree on the same diagnosis Can be measured in various ways:
- A reliability score of 0.7 means that a patient judged as 1. Concurrent validity → two different diagnostic systems
having schizophrenia by one clinician has a 70% chance of agree about the symptoms of mental health disorders. If
being diagnosed with Sz by another = good reliability diagnosis using the DSM comes up with the same mental
- Tested between two clinicians = increase inter rater disorder as a diagnosis using the ICD, then it will have
reliability concurrent validity
2. Test retest reliability → a diagnosis is reliable if it is 2. Predictive validity → the extent to which results from a
consistent over two different time periods for the same diagnostic tool e.g. DSM can predict future behaviour. If it
patient using the same psychiatrist and the same diagnosis leads to a treatment and can be used to predict how that
tool treatment will work on the patient = has predictive validity
Issues affecting the classification and diagnosis of Sz
SYMPTOM OVERLAP:
- Symptoms of Sz overlaps with other disorders so different psychiatrists may diagnose a different disorder instead of Sz =
diagnosis is unreliable. Incorrect diagnosis could take place = not valid e.g. Sz and bipolar disorder involve +ve symptoms e.g.
delusions and -ve symptoms e.g. avolition = questions reliability and validity of classification and diagnosis
- Most people who are diagnosed have enough symptoms of other disorders that they could also receive at least one other diagnosis
= validity of Sz as a single disorder can be questioned
- Ketter (05)- misdiagnosis due to symptom overlap = years of delay in recieving relevant treatment, during which time suffering
and further degeneration can occur as well as high level of suicide. Highlights symptom overlap as having serious concequences
and economic implication for the healthcare system
