Reliability and validity schizophrenia

Question 1

4 things to talk about in evaluation for diagnosis and classification for schizophrenia?

Answer 1

1. reliability
2. validity
3. co-morbidity
4. symptoms overlap

Question 2

reliability as evaluation

Answer 2

Reliability means consistency. Measure of reliability is inter-rater reliability to which different assessors agree on their assessment.

In this case of diagnosis this means to the extent two or more mental health professionals arrive at the same diagnosis for the same individual.

In 1962, Aron Beck measured inter-rater reliability of schizophrenia diagnosis and found that diagnosis made by doctors were around 52% similar. meaning doctors were often disagreeing with each other and diagnosis therefore lacked reliability.

• however inter-rater reliability was measured again in 2005 and found that diagnosis of schizophrenia were 81% similar. This suggests reliability is getting better over time.

Question 3

validity as evaluation

Answer 3

Validity is the extent to which we are measuring what we are intending to measure. One way to assess validity of diagnosis is criterion validity. Doing different assessments with the same diagnosis for the same person

• in 1973, Rosenhan got 8 volunteers to go to a mental health hospital.
• volunteers were mentally healthy but were told to pretend they were hearing voices so they can be admitted to hospital.
• once they were admitted to hospital Rosenhan asked them to start acting normal
• Rosenhan waited to see how long it would take doctors them to realise volunteers weren’t schizophrenic

he found that:
- when volunteer were behaving normally doctors saw them behaving as abnormal for instance when they writing in the notes in diary doctors reported that they had writing behaviour.
- doctors didn’t notice that they were actually healthy
- first volunteer was released after 7 days and last one was released after 52 days
- as result, doctors made incorrect diagnosis and there diagnosis lacked validity.

Question 4

co morbidity as evaluation

Answer 4

Co morbidity is when two or more conditions occur together. If conditions occur a lot at the same time then this calls into question the validity as might be a single condition.

• Buckley study investigated how many schizophrenics had co morbidity illness
• found 50% had co morbid depression
• 47% had addiction
• 23% had ocd
• this showed that patients who were diagnosed with schizophrenia had second illness.
• Buckley concluded that the way doctors divided up and categorise mental disorders might not be accurate for e.g given how co morbid they are maybe schizophrenia and depression aren’t two separate mental conditions and might be apart of same illness.
• therefore criteria used to diagnose schizophrenia might lack validity.

Question 5

overlapping symptoms
as evaluation

Answer 5

When there is overlap of symptoms between the symptoms. For e.g both schizophrenia and bipolar disorder involves positive symptoms like delusions and negative symptoms like avolition. This questions validity as misdiagnosis.

study support: Ellason and ross compared symptoms of disassociate identity disorder and schizophrenia and found that patients with disassociate identity disorder displayed more schizophrenic symptoms than people who have been diagnosed with schizophrenia.