Introductions to SZ Flashcards
What is SZ?
SZ is a severe mental disorder where contact with reality and insight are impaired.
Only experienced by around 1% of the population.
What are the 2 major systems for classification of mental disorders?
ICD-10
DSM-5
How do the 2 differ in classification of SZ?
In DSM-5, 2 or more positive symptoms are needed for a diagnosis ,whereas in the ICD-10 two or more negative symptoms are sufficient.
creates an issue of reliability and validity
What are positive symptoms?
Patient experiencing things beyond what is normally experienced.
E.g. Hallucinations and delusions.
What are Hallucinations?
- Unusual sensory experiences.
- Sometimes relating to things in the environment but often dont relate at all.
- Auditory hallucinations such as as hearing voices.
- Visual hallucinations such seeing things that are not there.
What are Delusions?
- Delusions are irrational beliefs, which can make you behave abnormally.
- Grandeur: Believing you are someone more important than you are.
- Persecution: Believing someone is after you.
- Reference: Something is reffered only to you.
What is Disorganised speech?
- Individuals speech is diffucult to understand.
- Speaking incoherently
- using made-up words
What are Negative symptoms?
The loss of usual abilities and experiences.
E.g. speech poverty and avolition.
What is Speech poverty?
- A reduction in the amount and quality of speech someone is producing.
- Delay in responses.
What is Avolition?
- Finding it difficult to begin or keep up with goal orientated behaviour.
- Signs of this are poor hygiene and grooming, lack of energy, lack of persistence in work or education.
What is Diminished emotional response?
- Your emotional expressions do not show outwardly.
- Speaking in a Dull flat voice.
One strength of the diagnosis of schizophrenia is its reliability.
Diagnosis is said to be reliable when different clinicians reach the same diagnosis on the same individual.
A researcher report excellent reliability for the diagnosis of schizophrenia in 180 individuals using the DSM-5. Pairs of interviewers achieved inter-rater reliabilty of + 97 and test-retest reliability of +.92.
This means that we can be reasonably sure that the diagnosis of schizophrenia is consistently applied.
One limitation of the diagnosis of schizophrenia is its validity.
In general validity concerns whether we assess what we are trying to assess.
One way to assess validity of a psychiatric diagnosis is criterion validity. A researcher had two psychiatrists independently assess the same 100 clients using ICD-10 and DSM-IV criteria and found that 68 were diagnosed with schizophrenia under the ICD system and 39 under DSM.
This suggests that schizophrenia is either over- or underdiagnosed according to the diagnostic system,this suggests that criterion validity is low.
Counterpoint to low validity of SZ.
In the Osório study reported above there was excellent agreement between clinicians when they used two measures to diagnose schizophrenia both derived from the DSM system.
This means that the criterion validity for diagnosing schizophrenia is actually good provided it takes place within a single diagnostic system.
Another limitation of schizophrenia diagnosis is its co-morbidity with other conditions
If conditions occur together a lot of the time then this calls into question the validity of their diagnosis and classification because they might actually be a single condition.
Schizophrenia is commonly diagnosed with other conditions. For example, one review found that about half of those diagnosed with schizophrenia also had a diagnosis of depression or substance abuse.
This is a problem for classification because it means schizophrenia may not exist as a distinct condition, and is a problem for diagnosis as at least some people diagnosed with schizophrenia may have unusual cases of conditions like depression.
A final limitation of schizophrenia diagnosis is symptom overlap with other conditions.
There is considerable overlap between the symptoms of schizophrenia and the symptoms of other conditions. For example, both schizophrenia and bipolar disorder involve positive symptoms (such as delusions) and negative symptoms (such as avolition).
In terms of classification this suggests that schizophrenia and bipolar disorder may not be two different conditions but variations of a single condition.
In terms of diagnosis it means that schizophrenia is hard to distinguish from bipolar disorder.
As with co-morbidity, symptom overlap means that schizophrenia may not exist as a distinct condition and that even if it does it is hard to diagnose. So both its classification and diagnosis are flawed.
