Schizophrenia Lesson 3 : The Reliability And Validity In The Diagnosis And Classification Of Schizophrenia Flashcards
What is reliability in the diagnosis of schizophrenia?
The idea that there should be a good consistency of diagnosis of schizophrenia over a period of time and between different psychologists
The reliability for diagnosing schizophrenia is more superior than others: 81% for schizophrenia and 63% for anxiety disorders
How can the reliability of diagnosis be measured?
Using inter rate reliability
Two different psychologists would both diagnose the illness of schizophrenia
(The diagnosis could then be correlated, and if there is a positive correlation coefficient of +0.8 or above
Which one is more reliable: the ICD-10 or the DSM-V
DSM-v
What is validity in diagnosing schizophrenia?
Whether or not the diagnostic system assess what it claims to be assessing
This is whether or not the ICD/DSM is really assessing schizophrenia
If the DSM and ICD are valid then we can be confident in saying that people who have been disgnosed with schizophrenia do actually have the disorder and not another
What is content validity in schizophrenia?
The extent to which an assessment covers the range of symptoms of schizophrenia
E.g. interviews or a check,it’s if schizophrenic symptoms that should cover all of the symptoms not just a few of them
What is co-morbidity?
A validity issue
The fact that two illnesses tend to occur with each other. E.g. schizophrenia occurs with depression and OCD
This is an important issue when considering the validity in diagnosing and classifying schizophrenia
Sweets (2014) - started that 1% of the population will suffer from schizophrenia and 2.5% from OCD.
However 12% of schizophrenic patients meet the diagnostic criteria to also be suffering OCD. This causes the problem of classifying the illness as schizophrenia and not other illnesses.
The boundaries between schizophrenia and mood disorders are BLURRED.
Evaluation points for co-morbidity
- Sim (2006) -
- Links of schizophrenia to drug use -
- Validity of research (Jeste) -
Evaluation point for co-morbidity 1: Sim 2006
He found that 32% of 142 hospitalised schizophrenic patients had additional mental disorders (co-morbid) which is a problem when diagnosing and classifying the illness
This means that the diagnosis of schizophrenia is invalid, and also unreliable
Evaluation point for co-morbidity 2: Links of schizophrenia to drug use
It has been found that schizophrenic patients have used alcohol, cannabis and cocaine and suffered from substance abuse before they were diagnosed with the illness and during the illness
This makes it difficult to give a valid diagnosis because the symptoms of schizophrenia are the same as those who use drugs, because bith lead to lower levels of functioning.
It makes it hard to use symptoms to directly diagnose schizophrenia because it questions which illness is being diagnosed via that symptom
Evaluation point for co-morbidity 3: validity of research jeste
Jeste conducted research and identified problems that would lead low levels of validity
He found that schizophrenic patients with co-morbid illnesses were often excluded from the research Pam but the majority of schizophrenic patients suffer with other psychological illnesses
Research findings from schizophrenia patients cannot be generalised to all patients and might be invalid overall
What is culture bias in schizophrenia?
A reliability and validity issue
Culture has an influence in the diagnosis and classification of schizophrenia
E.g. auditory hallucinations can be influenced by culture
Luhrmann interviewed 60 adults with schizophrenia ( 20 from Ghana, 20 from India and 20 for the USA)
All the patients reported hearing voices, but the patients from the USA reported the most negative experience associated with the voices
Therefore, culture has an influence on diagnosing reliability
Cochrane found that Afro-Caribbean people living in Britain were 7 times more likely to be diagnosed with schizophrenia than a white patient.
This means that either Afro Caribbean people have more stressors that cause schizophrenia, or their diagnosis of schizophrenia was invalid due to culture bias
