Lesson 3: The reliability and validity in the diagnosis and classification of schizophrenia (co-morbidity, culture bias, gender bias and symptom overlap): Flashcards
What is co morbidity
Co-morbidity (AO1) (Validity issue)
This refers to the extent that two or more conditions occur simultaneously/coexist in the same individual at the same time (co-exist alongside each other.) Therefore a person with schizophrenia might also be suffering from another condition such as depression.
This is an important issue when considering the validity in diagnosing and classifying schizophrenia. Swets (2014) stated that 1% of the population will suffer from schizophrenia and 2.5% from OCD. However, 12% of schizophrenic patients meet the diagnostic criteria to also be suffering from OCD (co-morbid). This causes the problem of classifying the illness as schizophrenia, and not OCD.
The boundaries between schizophrenia and mood disorders are blurred, and both types of illnesses share many symptoms. There is the problem that depression (a mood disorder) is co-morbid (occurs alongside) schizophrenia. This means that full consultation using the DSM and ICD must be used in order to get the correct and valid diagnosis of the illness.
Evaluation for co morbidity
1) The DSM and ICD can be criticised because they can be viewed as lacking validity. There is too much of an overlap between schizophrenia, mood disorders and OCD. Sometimes clinicians might classify the patient as having schizophrenia and depression (co-morbid) as a way to get round the problem of making a judgement between schizophrenia and depression. Sometimes a second opinion from another clinician might be required in order to make an accurate and valid diagnosis. (-)
2) Research conducted by Sim (2006) found that the diagnosis of schizophrenia can be invalid and unreliable because of the issues surrounding co-morbidity. He found that 32% of 142 hospitalised schizophrenic patients had additional mental disorders (co-morbid), which is a problem when diagnosing and classifying the illness. (-)
3) Co-morbidity can be a problem when diagnosing schizophrenia. It has been found via research that schizophrenic patients have used alcohol, cannabis and cocaine and suffer from substance abuse before they were diagnosed with the illness (as well as during their illness). This makes it incredibly difficult to give a reliable and valid diagnosis of schizophrenia, because some of the symptoms of the illness are the same as those who use drugs and alcohol (co-morbid). (-)
4) Jeste (1996) conducted research and identified problems that would lead to low levels of validity. He found that schizophrenic patients with co-morbid illnesses were often excluded from research, but the majority of schizophrenic patients do actually suffer with other psychological illnesses. Research findings from schizophrenia patients cannot be generalized to all patients and might be invalid overall (-)
What is cultural bias
Culture bias: (AO1) Reliability & validity issue
a) Culture has an influence on the diagnosis and classification of schizophrenia. For example, “hearing voices” (auditory hallucinations) can be influenced by culture. Luhrmann (2015) interviewed 60 adults with schizophrenia, (20 from Ghana, 20 from India and 20 from USA), all of the patients reported that they heard voices, but the patients from the USA reported the most negative experiences associated with the voices, e.g. the voices were violent and hateful. Therefore culture has an influence on the reliability of diagnosing schizophrenia.
b) Davison and Neale (1994) explain that in Asian cultures, some people are praised if they do not show that they are suffering from an emotional/psychological problem, therefore people from Asian cultures might be unlikely to seek psychological help if they have schizophrenia (and therefore these people will not appear in any stats). In Arabic cultures, people are encouraged to show emotions, and therefore this culture might be more likely to seek help for schizophrenia if they have it and there might be more stats and data available for this group. Therefore there is a cultural bias.
Cultural bias evaluation
1) A negative point about diagnosing and classifying schizophrenia is cultural relativism. The psychologist might not be able to understand the patient’s symptoms correctly due to not fully understanding the patient’s cultural background, and might misdiagnose schizophrenia. The psychologist might also wrongly label the patient as schizophrenic if the psychologist makes incorrect judgements about the patient in terms of their cultural background. Also some people from an African background might be wrongly diagnosed with schizophrenia due to the fact that they might claim that they can hear the voice of God (due to religion). In the African culture, these people would be seen as gifted; however in the western world this could be interpreted as a hallucination (auditory), and could be judged as being a symptom of schizophrenia, which could lead to an incorrect and invalid diagnosis. (-)
2) Research evidence has found support for cultural relativism. Afro-Caribbean people have little immunity to flu, and children born to mothers who had flu when they were pregnant in their second trimester, have an 88% increased chance of developing schizophrenia. Therefore there might be a cultural vulnerability which means Afro-Caribbean’s might be more at risk from developing schizophrenia than the white population (+)
3) Barnes (2004) suggested there is supporting research evidence for cultural differences when diagnosing and classifying schizophrenia. The Ethnic Culture hypothesis predicts that ethnic minorities experience less distress if they suffer with the illness of schizophrenia, because they have protective characteristics and social structures that exist in their culture. 184 individuals with schizophrenia were investigated from African American, Latino or White American cultures. It was found that Americans had more symptoms than the other 2 cultures because they had less protective and supportive features in their culture (social support). (+)
What is gender bias
Gender bias (AO1) Validity issue:
The accuracy of diagnosing schizophrenia can be dependent on the gender of the patient which leads to a gender bias occurring. Male sufferers of schizophrenia tend to show more negative symptoms than women, and also seem to suffer from more substance abuse. Males have an earlier onset (aged 18-25 years) of schizophrenia than females (25-35 years).
There seems to be great disagreement amongst clinicians when diagnosing schizophrenia, especially when the factor of gender is taken into account. The accuracy of diagnosis can vary due to clinicians having stereotypical beliefs about gender. Critics of the DSM argue that healthy adult behaviour is linked more to healthy males rather than healthy females. Therefore the DSM could be viewed as being gender biased, especially when trying to classify and diagnose the symptoms of schizophrenia, which might be invalid.
Gender bias evaluation
Evaluation (AO3)
1) There is a problem of gender bias occurring when diagnosing schizophrenia and research support comes from Loring (1985). He gave 290 male and female psychologists case studies of patients to read (one male and one female). Psychologists had to judge the patients using diagnostic criteria. When the patient was described as male, or no information was given about gender, 56% of psychologists diagnosed the patient as schizophrenic. When the patient was described as female, 20% of the psychologists diagnosed schizophrenia. Therefore there is a gender bias when diagnosing schizophrenia, and this was especially prominent when the psychologist was male. (-)
2) The validity of the diagnosis of schizophrenia can be questioned, especially as it seems that females develop schizophrenia 4-10 years later than males do. There are different types of schizophrenia that males and females are vulnerable to, so this must be taken into account when diagnosing and classifying the illness. (-)
3) Research evidence by Kulkarni (2001) has found supporting data to suggest that females might be less vulnerable than males to schizophrenia. He found the female sex hormone estradiol can help treat schizophrenia in females, especially when added to anti-psychotic drugs. It seems that estradiol might be a protective factor present in females that might lower their chances of getting schizophrenia compared to males. Clinicians must take this into account when diagnosing schizophrenia, especially in females, in order to ensure the diagnosis is valid. (+)
What is system overlap
The positive and negative symptoms of schizophrenia are a valid diagnosis of schizophrenia, however some of the symptoms of schizophrenia can also be found in the other disorders such as depression and bipolar disorder, and this is called symptom overlap which means that shared symptoms could lead to an incorrect and invalid of diagnosis.
Ross (1995) found that patients who had Dissociative Identity Disorder had many symptoms which overlapped with schizophrenia, so much so, that they could have been diagnosed with schizophrenia!
Other illnesses that seem to show symptom overlap with schizophrenia include:
• Bipolar depression (depressed mood, episodes of mania/energy, unpredictable, hallucinations delusions)
• Depression (hallucinations)
• Schizotypal personality disorder (similar symptoms of schizophrenia, but milder)
The person may exhibit a symptom typical of schizophrenia (e.g. delusions) but they could instead have another condition with the same symptom (e.g. bipolar disorder).
System overlay evaluation
1) To support a correct diagnose of schizophrenia in a valid way, clinicians should conduct a brain scan or EEG. This can examine the brain in detail and especially check the grey matter in the brain (where intelligence is held). Schizophrenic patients tend to suffer from a deterioration of grey matter, and this can be checked by conducting a brain scan. Patients who have bipolar depression do not have a reduction in grey matter. (+)
2) A problem of symptom overlap is that it can cause misdiagnosis of schizophrenia. Ketter (2005) found evidence of schizophrenia being misdiagnosed as another illness, because of symptom overlap. This causes years of delays, whereby schizophrenia patients do not receive the necessary treatment that they actually need, and their illness gets worse. This can increase rates of suicide and deterioration. Therefore it is important than patients get a valid and accurate diagnosis in the first place. (-)
3) Research evidence has supported the idea that inter rater reliability is actually quite low, especially when asking psychologists to agree on diagnosing schizophrenia and not another illness. Beck (1961) studied 154 patients who met with two different psychiatrists. It was found that inter rater reliability was 54%, which means that there was 54% agreement between the two psychiatrists in terms of diagnosis of the illness schizophrenia. This therefore suggests that different psychiatrists might give different diagnosis to the same patient who display the same symptoms of schizophrenia (-)
Explain study by Rosenhan
Part 1:
• Hypothesis: Psychiatrists cannot reliably distinguish schizophrenics from non-schizophrenics
• Rosenhan questioned the validity of classification and diagnosis of schizophrenia
• Field experiment in the USA
• 8 sane people sought admission to 12 separate hospitals (pseudo patients)
• Patients claimed they had auditory hallucinations and heard the words, “thud, hollow and empty”
• When admitted to hospital they stopped showing schizophrenic symptoms and behaved normally
• Pseudo patients made notes of their experience.
• All pseudo patients except one were given the diagnosis of schizophrenia
• The pseudo patients remained in hospital from 7-52 days
• 35 out of 118 genuine patients suspected the pseudo patients to be, “sane”
• The mentally ill are better at diagnosing schizophrenia than the psychiatrists!
• Conclusion – psychiatrists cannot detect the sane from the insane and the diagnosis and classification of schizophrenia is unreliable
Part 2
• Hospital staff were informed by Rosenhan that pseudo patients might seek admittance in the next 3 months.
• Out of 193 patients, 41 were confidently judged to be pseudo patients by staff, and another 23 were suspects.
• Rosenhan sent no pseudo patients at all. All patients were genuine
• Rosenhan concludes that psychiatrists cannot detect the sane from the insane and diagnosis of schizophrenia is unreliable
Rosenhan study evaluation
1) A problem of this study us the time era it was conducted in. Diagnostic procedures have improved since Rosenhan’s study. Psychologists would be using the DSM-V and ICD-11 nowadays in order to reliably diagnose and classify schizophrenia effectively. Also to ensure reliability further, two psychiatrists would need to agree that a patient has schizophrenia, so that the diagnosis would be valid and reliable. The psychologist Spitzer argued that this failed to happen in Rosenhan’s study and might make the diagnosis unreliable (-)
2) We must be cautious when criticising the study by Rosenhan. If a patient shows up at a hospital showing symptoms of schizophrenia, most psychiatrists would measure those symptoms (validity) and then make a judgement about whether the patient has the illness. If someone behaves like a schizophrenic, then it could be fair to say that psychiatrists are doing their duty by diagnosing the illness of schizophrenia and admitting the patient to hospital. To turn the patient away could be negligent. Could we argue that the psychologists made the correct and valid decision to admit the patients to hospital thinking they needed help? (+)
3) The study by Rosenhan raises many problems. If we accept the statement by Rosenhan that psychiatrists cannot detect the sane from the insane, then this means that psychiatrists cannot be trusted to accurately and reliably make a diagnosis about schizophrenia. If psychiatrists are in doubt when diagnosing the illness of schizophrenia, then they should seek a second opinion from a colleague, preferably a consultant who has more experience in the field. This would help increase the validity and reliability when diagnosing a patient with schizophrenia (-)
