Validity

Question 1

In relation to schizophrenia, what is meant by validity?

Answer 1

The extent to which schizophrenia is a unique disorder with characteristics and symptoms.

Question 2

What is meant by criterion validity?

Answer 2

The extent to which different classification systems produce the same diagnosis in patients - systems should be correlated and produce same results.

Question 3

What is meant by predictive validity?

Answer 3

Where the diagnosis of SZ leads to successful treatment.

Question 4

What is meant by descriptive validity?

Answer 4

The extent to which schizophrenia is a separate disorder - patients with SZ should be different to those with bipolar disorder.

Question 5

What is meant by aetiological validity?

Answer 5

The extent to which all patients with schizophrenia have the same cause.

Question 6

What is meant by aetiologically heterogeneous?

Answer 6

The idea that different combinations of genes cause mental disorders.

Question 7

What can get in the way of the validity of schizophrenia?

Answer 7

Co-morbidity, symptom overlap, gender bias and culture bias.

Question 8

What is one weakness of the validity of schizophrenia?

Answer 8

1. Research suggests there is poor criterion validity (CV) with SZ diagnosis.
   Cheniaux et al: same sample diagnosed differently according to ICD and DSM - more diagnosed with SZ with ICD.
   Shows there is no set category for SZ as there is no good correlation between classification systems.
   Therefore, diagnosis of SZ has low CV as, those who don’t have SZ may be diagnosed.

Question 9

What is a second weakness of the validity of schizophrenia?

Answer 9

2. Issues with co-morbidity when diagnosing SZ.
   Buckley: half of those diagnosed with SZ were also diagnosed with depression + 23% with OCD.
   Suggests SZ may not exist as a distinct separate illness - shows there are issues with how SZ is classified which can lead to problems with diagnosis e.g atypical case of depression may be diagnosed as SZ.
   Therefore, SZ has poor descriptive validity as, there is too much co-morbidity which suggests SZ may not be told apart from cases of depression or OCD.

Question 10

What is a third weakness of the validity of schizophrenia?

Answer 10

3. There are issues with symptom overlap when diagnosing SZ.
   Bipolar and SZ share some symptoms making it hard to distinguish between the two.
   Shows there is a possibility someone may be incorrectly diagnosed with bipolar when they actually have SZ.
   Therefore, may lead to incorrect treatment which will worsen disorder.