The Genetic Explanation of Schizophrenia

Schizophrenia Description of symptoms and features thought insertion, hallucinations, delusions, disordered thinking. Biological Cause: The function of neurotransmitters Biological Cause: Genetics Cognitive Cause: Attention deficient theory Biological Treatment: Medication Cognitive Treatment: CBT

Key word challenge: AS revision How strong are you genes? How would you test to see the strength of the genetic explanation of Schizophrenia? What is the prevalence of Schizophrenia in the general population? Key word challenge: AS revision https://www.ncbi.nlm.nih.gov/pubmed/6151205

Key Terms nature, nurture, concordance rate, adoption studies, twin studies, monozygotic, dizygotic, C4 gene, pruning, genomes, synaptic pruning, C4-A, biomarker, Studies: Gottesman and Shields (1966) Heston (1966) Sekar et al. (2016)

Studies and articles to explore AO1: AO3: Priming our brains nature, nurture, concordance rate, adoption studies, twin studies, monozygotic, dizygotic, C4 gene, pruning, genomes, synaptic pruning, C4-A, biomarker,

Gottesman and Shields (1966) Type of Study: Aim: Hypothesis: Location: Duration: Eligible: Attrition: 1. Testing Zygocity 2. Testing Schizophrenia Concordance rate: Conclusion: MZ DZ Schizophrenia Severe Schizophrenia (+2 years in hospital)

Heston (1966) Type of Study: Adoption Study Aim: to investigate whether removing a child from its schiozophrenogenic mother has an impact on the rate of schizophrenia. Hypothesis: SZ is due to a distorted family environment. Location: Eligible: Attrition: death, Matched on: sex, placement type, length of time in care Assessing psychiatric status: 2 psychologist + Heston + Hospital Results: Conclusion: Control Schizophrenia More than 1 year in hospital or penal institution Psycho-social disfunction

C4: Synaptic Pruning https://www.youtube.com/watch?v=8J-JflThHks https://www.youtube.com/watch?time_continue=9&v=s0y4equOTLg C4 gene, pruning, genomes, synaptic pruning, C4-A, biomarker Immune system Excessive synaptic pruning during Increased complement (C4) activity, could lead to the cognitive symptoms seen in schizophrenia.

Issues and Debates + SODAR AO3: Evaluation Issues and Debates + SODAR Ethics Practical Issues Reductionism Culture and Gender Psychology as a Science Comparison of Themes Nature and Nurture Development over time Social Sensitivity Usefulness/Application Social Control Supporting Evidence Opposing the supporting evidence Different theories Application Reductionism

AO3: Evaluation Strengths Weaknesses

Thinking about your evaluation points How do the findings compare to the probability of a random member of the general population suffering from schizophrenia? What should concordance be for MZ twins if genetics was the only explanation? Is there another explanation for high concordance amongst family members, particularly identical twins? What about those people diagnosed with the disorder but who have no relatives suffering from it? Are the concordance rates for twin studies similar? Why is concordance for MZ twins always higher than that for DZ twins? What is the problem with retrospective data? If diagnostic criteria has changed over time how will it affect the research findings? What is the Diathesis stress model/ What is the social causation hypothesis?

Possible Exam Questions (12/16/20 marks) Evaluate one other biological explanation of Schizophrenia. To what extent can the other biological explanation be used to explain the development of Schizophrenia. Discuss two practical issues that researchers may encounter when investigating the other biological explanation of Schizophrenia. Assess the biological explanations of Schizophrenia.