L3: Reliability & Validity of Classifying & Diagnosis of Schizophrenia

Question 1

What are the 4 issues?

Answer 1

Co-morbidity
Culture bias
Gender bias
Symptom overlap

Question 2

AO1 of Co-morbidity

Answer 2

• Extent that 2+ illnesses occur simultaneously
• 1% of population suffer from schizophrenia and 2.5% suffer from OCD
• 12% of Schiz patients meet criteria for OCD, make it hard to classify correctly (invalidity)
• Boundaries between illnesses are blurred as both illnesses share some symptoms
• Depression is comorbid with Schiz, so categorising is difficult

Question 3

AO3 of Co-morbidity

Answer 3

(-) DSM & ICD criticised for lacking validity. Too much overlap between OCD, Schiz and mood disorders. Some clinicians might categorise a patient as one thing, but another would put them in a different category. A second opinion is essential
(-) Research found diagnosis of Schiz can be invalid and unreliable because of comorbidity. 34% of 142 hospitalised Schiz patients had additional mental disorders
(-) Schiz patients have suffered substance abuse before they were diagnosed. Makes it difficult to make a reliable/valid diagnosis as some symptoms of the illness are the same as those who use drugs
(-) Research shows low levels of validity. Patients with co-morbid illnesses were excluded from research, but the majority of patients do suffer with other illnesses. Therefore findings cannot be generalised and might be invalid overall.

Question 4

AO1 of Culture Bias

Answer 4

• Hearing voices can be influenced by culture. 60 adults with Schiz were interviewed, all heard voices but patients from the USA reported most negative experiences. Voices were violent and hateful. Culture has an influence on the reliability of diagnosing Schiz.
• In Asian cultures, people are rewarded if they do not show they are suffering so are unlikely to get help. In Arabic cultures, people are encouraged to show emotions and are likely to seek help. There is a cultural bias when examining the No. of people from diff cultures who suffer from Schiz.

Question 5

AO3 of Culture Bias

Answer 5

(-) Cultural Relativism: psychologist may not understand patients symptoms correctly because of misunderstanding their cultural background. They might misdiagnose Schiz or wrongly label the patient. Some people with African backgrounds might be misdiagnosed as they ‘hear the voice of God’, they would be seen as gifted in their culture, but might be seen as a delusion, a symptom of Schiz, leading to an invalid diagnosis.
(+) Evidence for cultural relativism: Afro-Caribbean people have little immunity to flu, and children born to mothers who had the flu whilst in the second trimester have an 88% increased chance of developing Schiz, and there might a cultural vulnerability .
(+) Evidence for cultural differences. The ethnic culture hypothesis predicts that ethnic minorities experience less distress if they have Schiz as they have protective characteristics and social structures in their cultures. 184 Schiz patients were invested from Latino, African-American or White American cultures. Americans had more symptoms because they had less protective features in the culture

Question 6

AO1 of Gender Bias

Answer 6

• Males show more negative symptoms & suffer more from substance abuse
• Males have earlier onset
• Disagreement between clinicians with diagnosing when gender is involved. Accuracy can vary from stereotypical beliefs about gender
• Critics of DSM say healthy behaviour is linked to healthy males rather than healthy females so it is gender biased and could be invalid

Question 7

AO3 of Gender Bias

Answer 7

(-) 290 male and female psychologists got case studies (one male and female), and had to diagnose them according to the criteria. When the patient was given no gender or presented as male, 56% of psychologists diagnosed them as Schiz. When patient was female, no. lowered to 20%. Shows there is a gender bias during diagnosis, most prominent with male psychologists
(-) Validity can be questioned as females develop Schiz 4-10 years later than males. There are diff types of Schiz that the genders are vulnerable to, and this must be taken into account
(+) Females might be less vulnerable to Schiz. The sex hormone estradiol helps treat Schiz in females esp when added to anti-psychotic drugs. Might be a protective factor, lowering their chances of getting Schiz.

Question 8

AO1 of Symptom Overlap

Answer 8

• Positive & Negative symptoms are valid but overlap with other disorder. This can affect validity.
  Patients who have Dissociative Identity Disorder had many symptoms overlapping with Schiz, that they could have been diagnosed as Schiz.
• Other illnesses overlapping symptoms are Bipolar disorder, Depression, Cocaine intoxication, Schizotypal personality

Question 9

AO3 of Symptom Overlap

Answer 9

(-) Can cause misdiagnosis. Evidence Schiz being misdiagnosed because of symptom overlap. This causes years of delays and the illness gets worse, increasing rates of suicide.
(-) Inter-rater reliability is low, 154 patients met with 2 psychiatrists. Inter-rater reliability was 54%, suggests psychiatrists give different diagnosis to the same patient who displays the same symptoms of Schiz.
(+) To improve validity, clinicians should conduct a brain scan to check the grey matter where intelligence is held. Schiz patients experience a deterioration of grey matter and the brain scan can be used to check this to check the right illness has been diagnosed. Bipolar disorder does not result in loss of grey matter