Issues In Diagnosing Schizophrenia

Question 1

Define reliability

Answer 1

An examination of how consistent and stable the results of an assessment are

Question 2

Define validity

Answer 2

Refers to how well a test actually measures what it was created to measure

Question 3

Define content validity

Answer 3

Refers to the extent to which a test measures a representative sample of the study

Question 4

What is co-morbidity?

Answer 4

• validity issue
• refers to the extent that two or more illnesses occur simultaneously in a patient
• e.g. schizophrenia and depression

Question 5

Why is co-morbidity an issue?

Answer 5

• the boundaries between schizophrenia and mood disorders are blurred
• both illnesses share many symptoms
• can cause problems with misdiagnosis or choosing which disorder to diagnose

Question 6

Evaluate co-morbidity

Answer 6

(-) the DSM-V and the ICD-10 can be criticised for lacking validity. There is too much overlap between disorders. A second opinion may be needed for a valid and accurate diagnosis.

(-) Sim (2006) found diagnosis can be invalid and unreliable. 32% of hospitalised patients were co-morbid, which is a problem when classifying and diagnosing.

(-) research shows patients suffered from substance abuse prior to diagnosis. Some symptoms of sz. and substance abuse are similar, making it difficult to make a reliable & valid diagnosis.

(-) Jeste (1996) identified problems that lead to low validity. Co-morid patients were excluded from studies even though the majority suffer from more than one illness. Findings can’t be generalised.

Question 7

Why is culture bias an issue?

Answer 7

• affects reliability and validity
• Luhrmann (2015) interviewed 60 patients (Ghana, India, USA). USA reported most negative experiences with auditory halluncinations. [influences reliability]
• Davidson and Neale (1994) explains some cultures praise / reward those who hide their suffering. In Asia, sufferers may be reluctant to seek help whilst in cultures that are encouraged to show emotions are more likely to seek help. [affects number of people of different cultures in studies]

Question 8

Evaluate culture bias

Answer 8

(+) research evidence for cultural relativism. Afro-Carribbean people have little immunity to the flu. Mothers that have this during their pregnancy have children with an 88% increased chance of developing sz.

(+) Barnes (2004) investigated 184 patients (African American, Latino, White American). Americans had more symptoms bc they had less protective / supportive features in their culture (social support)

(-) Cultural Relativism. Psychologist may not be able to undertand symptoms bc of not understanding their cultural background. Can lead to incorrect judgements and invalid diagnosis.

Question 9

Why is gender bias an issue?

Answer 9

• affects validity
• males tend to show more negative symptoms than women
• males have an earlier onset (18-25) than females (25-35)
• DSM is gender bias [healthy behaviour linked to males]

Question 10

Evaluate gender bias

Answer 10

(+) Kulkarni (2001) found data that suggest females may be less vulnerable to sz. Estradiol is a hormone that can help treatments, and is a protective factor. This is taken into account when diagnosing.

(-) Loring (1985) gave 290 psychologists case studies to diagnose. Male patients were diagnosed schizophrenic by 56% of psychologists; females had 20% psychologist diagnose them.

(-) validity of diagnosis can be questioned especially as females tend to develop sz 4-10 yrs later. There are different subtypes that either gender is vulnerable to - this needs to be taken into consideration when diagnosins.

Question 11

What is symptom overlap?

Answer 11

When two or more disorders share some of the same symptoms needed for classification.

Question 12

What other illnesses show symptom overlap with schizophrenia?

Answer 12

• bipolar depression (depressed mood, mania, unpredictable, hallucinations, delusions)
• depression (hallucinations)
• cocaine intoxication (paranoia, disorganised speech, delusions)
• schizotypal personality disorder (same but milder symptoms)

Question 13

Evaluate symptom overlap.

Answer 13

(+) all clinics shoukd conduct a brain scan / EEG to examine the brain in detail, checking the grey matter. Sz patients have reduced grey matter, other illnesses may not have reduced grey matter.

(-) Ketter (2005) found evidence of sz being misdiagnosed for another illness. This causes delays in treatment, this makes symptoms worse - leads to higher suicide and deterioration rates.

(-) Beck (1961) studied 154 patients who met two different psychiatrists. Inter rater reliability was 54%. Different psychiatrists might give different diagnosis to the same patients.