Paper 3: Schizophrenia Flashcards
- Classification and diagnosis of Schizophernia
One strength
P: strength of schizophrenia diagnosis is its high reliability when using the same diagnostic instrument
Eg: Osorio et al. (2019) evaluated the diagnosis of schizophrenia using the DSM-5 and showed excellent inter-rater reliability, with a kappa score of 0.97.
Ex: This demonstrates that when psychiatrists apply standardized diagnostic criteria consistently, such as the DSM-5, they can reliably identify schizophrenia across different cases. High reliability is essential because
accurate and consistent diagnosis ensures patients receive appropriate treatment, which can improve prognosis and quality of life.
C: However, while reliability is high with the DSM-5, it does not guarantee validity; psychiatrists may agree on a diagnosis that still fails to accurately reflect the underlying condition. This highlights the need for continued research into the biological and psychological markers of schizophrenia.
L: Nevertheless, the findings suggest that the application of standardized tools like the DSM-5 play a critical role in improving diagnostic consistencv in clinical practice.
- Classification and diagnosis of Schizophernia
Two limitations
P: A limitation of schizophrenia diagnosis is its lack of inter-rater reliability.
Eg: Cheniaux et al. (2009) had two psychiatrists independently diagnosed 100 patients using both the ICD and DSM criteria. The first psychiatrist diagnosed 26 patients with schizophrenia using DSM and 44 using ICD, while the second psychiatrist diagnosed only 13 with DSM and 24 with ICD.
Ex: This demonstrates that there is inconsistency between psychiatrists and diagnostic systems, meaning the diagnosis of schizophrenia is not reliable. As a result, the diagnosis and treatment of schizophrenia may depend more on the psychiatrist consulted rather than the actual symptoms presented.
L: This limits the validity and reliability of the diagnostic process, leading to potential misdiagnosis, incorrect prognosis, and inappropriate treatment plans.
A limitation of schizophrenia diagnosis is the issue of symptom overlap, which reduces its validity.
Lichtenstein et al. (2009) found that schizophrenia and bipolar disorder share common genetic causes, suggesting the overlap in symptoms may reflect underlying biological similarities. This raises questions about whether
schizophrenia is a distinct disorder at all.
Symptom overlap occurs when two or more conditions share similar symptoms, such as schizophrenia and bipolar disorder. Under the ICD, a patient may be diagnosed with schizophrenia, whereas the same patient could be diagnosed with bipolar disorder using the DSM. This inconsistency highlights problems with the classification systems, as they treat these conditions as separate despite significant symptom similarities.
L: Such findings reduce the validity of diagnosis because the boundaries between disorders appear unclear.
Furthermore, this limits the reliability of classification systems, as they fail to consistently differentiate between conditions, undermining their accuracy and generalisability in clinical practice.
- Biological explainations of SZ
One strength
A strength of the genetic argument for schizophrenia is that there is robust evidence showing a clear link between genetic relatedness and the risk of developing the disorder
Eg: Gottesman (1991) demonstrated that the closer the degree of genetic relatedness, the greater the risk of developing schizophrenia. Adoption studies, such as Tienari et al. (2004), further support this by showing that children of schizophrenia sufferers are at heightened risk of developing the disorder even when adopted into families with no history of schizophrenia.
This provides overwhelming evidence that genetic factors increase susceptibility to the condition, highlighting the role of biological inheritance.
However, while genetics appear to play a significant role, they may not be the only factor involved. Environmental influences, such as stress or family dynamics, likely interact with genetic vulnerability to trigger the onset of schizophrenia.
This supports the validity of the involvement of genetics, but proposes a diathesis-stress model, where genetics create a predisposition that may require environmental factors to manifest fully.
