Question 112 marks
Question
(a) Explain what is meant by ‘schizophrenia’. [2] (b) Describe the genetic explanation of schizophrenia, as outlined by Gottesman and Shields (1972).[4] (c) Explain one similarity and one difference between cognitive and genetic explanations of schizophrenia.[6]
Mark scheme
1(a) Explain what is meant by ‘schizophrenia’. 2 Award 1 mark for a basic explanation of the term/concept. Award 2 marks for a detailed explanation of the term/concept. For example: Schizophrenia is a mental health disorder that involves positive and negative symptoms (1). Positive symptoms include things such as hallucinations and delusions (1). Negative symptoms might include speech poverty and flattening of mood (1). It is a break from reality where the person experiences symptoms such as hallucinations and delusions (1). Hallucinations are a positive symptom of schizophrenia (1). Types of schizophrenia are no longer on the syllabus, but can be credited, only up to a maximum of 1 mark if this is all that is given (e.g. simple, paranoid, catatonia, delusional disorder, etc.) Other appropriate responses should also be credited. 1(b) Describe the genetic explanation of schizophrenia, as outlined by 4 Gottesman and Shields (1972). Award 1–2 marks for a basic answer with some understanding of the topic area. Award 3–4 marks for a detailed answer with clear understanding of the topic area. For example: Schizophrenia appears to have a genetic cause as shown by Gottesman and Shields in their review of studies of adoption, siblings and twins with schizophrenia (1). All adoption studies found an increased incidence of schizophrenia in adopted children with a schizophrenic biological parent (1). Biological siblings of children with schizophrenia showed a much higher percentage of schizophrenia (1). All twin studies found a higher concordance rate for schizophrenia in monozygotic (MZ) than dizygotic (DZ) twins (1). In Gottesman and Shield’s own study the rate was 58% for identical twins, and 12% for non-identical twins (1). There is a heavy genetic input into the onset of schizophrenia (1). Other appropriate responses should also be credited. 1(c) Explain one similarity and one difference between cognitive and genetic 6 explanations of schizophrenia. Comparison will be for the cognitive explanation as outlined by Frith (1992) and the genetic explanation as outlined by Gottesman and Shields (1972). Similarities Both Gottesman and Frith believe that there is a biological basis for schizophrenia. Gottesman focusses on genetics and Frith also believes that genetics plays a part in the development of schizophrenia. Gottesman found a high concordance rate between MZ twins. Frith suggests that brain structure and biochemical processes also influence the development of the disorder. This shows that both explanations suggest a biological basis for the disorder. Both suggest nature is important in the development of schizophrenia – Gottesman suggests schizophrenia has a strong genetic cause and Frith suggests that schizophrenia cognitive difficulties are linked to genetics, brain structure and biochemical processes. Offer an individual explanation of schizophrenia. Gottesman suggests that one’s individual genetic make-up causes schizophrenia and not environmental factors. Frith suggests it is the person’s individual faulty mental processing (likely caused by biological factors) that lead to the development of the disorder and not environmental or social factors. Both explanations are backed up by experiments. Gottesman and Shields did many studies on twins and families to prove the genetic explanation of schizophrenia. Frith did a lab study where schizophrenic participants were unable to identify whether items that had been read aloud were done by a computer, the experimenter or themselves which shows the attention difficulties patients with schizophrenia have. Differences Frith also brings in a cognitive explanation of why the symptoms occur which is not done by Gottesman and Shields. Gottesman and Shields focus on the genetic cause of the disorder. Frith adds to this explanation by explaining the symptoms of the disorder due to faulty mental processing. Genetic explanation is more reductionist than the cognitive explanation. Gottesman and Shields just focus on the genetic cause of the disorder and do not consider other biological processes or cognitive explanations. Frith considers both biological causes and how these could lead to cognitive deficits such as faulty mental processing. 1(c) Mark according to the levels of response criteria below: Level 3 (5–6 marks) • Candidates will show a clear understanding of the question and will include one similarity and one difference. • Candidates will provide a good explanation with clear detail. Level 2 (3–4 marks) • Candidates will show an understanding of the question and will include one appropriate similarity in detail or one appropriate difference in detail. OR one similarity and one difference in less detail. • Candidates will provide a good explanation. Level 1 (1–2 marks) • Candidates will show a basic understanding of the question and will attempt a similarity and/or difference. This could include both but just as an attempt. • Candidates will provide a limited explanation. Level 0 (0 marks) No response worthy of credit. Other appropriate responses should also be credited.