Reliability and Validity

Question 1

What is validity?

Answer 1

The accuracy of a diagnosis.
One way to assess is through different assessment systems (ICD-10 or DSM-V)

Question 2

What is reliability?

Answer 2

The consistency in diagnosis.
Clinicians must be able to diagnose schizophrenia at two different points in time, using test-retest or inter-rater reliability

Question 3

What effects the validity of diagnosing schizophrenia?

Answer 3

Symptom overlap
Co-morbidity
Gender bias

Question 4

What is symptom overlap?

Answer 4

Symptoms of schizophrenia overlap with other mental health disorders

Question 5

What is co-morbidity?

Answer 5

Refers to two or more mental health disorders occurring at the same time

Question 6

What is gender bias?

Answer 6

Accuracy of diagnosis is dependent on the gender of the patient, possibly due to male-centric research evidence

Question 7

Validity AO3 - Evidence for symptoms overlap

Answer 7

Konstantareas and Hewitt - found that when comparing 14 schizophrenic patients with 14 autistic patients, 7 of the autistic patients showed symptoms of schizophrenia, lowering the validity of the diagnosis

Question 8

Validity AO3 - Evidence for gender bias

Answer 8

Loring and Powell (1998) - found when giving female and male psychiatrists the description of a schizophrenic patient, 56% of the male psychiatrists gave a schizophrenia diagnosis whereas only 20% of female psychiatrists gave one. Gender bias wasn’t present in the females, suggesting psychiatrists may be over-diagnosing males and under-diagnosing females, weakening the validity

Question 9

Validity AO3 - Inaccurate diagnosis

Answer 9

Rosenhan (1973) - admitted 8 pseudo patients in different hospitals in America, who claimed they heard voices, then they all acted normally. They were all diagnosed with schizophrenia, suggesting the diagnosis of schizophrenia lacks validity as psychiatrist cannot distinguish between real and pseudo patients

Question 10

What affects the reliability of diagnosing schizophrenia?

Answer 10

Cultural bias

Question 11

What is cultural bias?

Answer 11

Making judgement through a narrow view based on ones own culture

Question 12

Reliability AO3 - Evidence of cultural bias

Answer 12

Copeland (1971) - gave 134 US and 194 UK psychiatrists the description of a patient and 69% of the US psychiatrists gave a schizophrenia diagnosis and only 2% of UK psychiatrists gave one

Question 13

Reliability AO3 - Issues being evident

Answer 13

Mojtabi and Nicholson (1995) - asked 50 psychiatrists to differentiate between bizarre and non-bizarre delusions, and found the inter-rater reliability co-efficient to be 0.4 (0.8 is reliable) suggesting psychiatrists have inconsistencies in diagnosing