Genetic Explanations

• What do most modern mental health professionals believe about schizophrenia's origin?

  It is partly biological in origin
• What three explanations for schizophrenia will be considered?

  Genetic vulnerability, dopamine role, brain structure
• How are genetic vulnerability, dopamine, and brain structure related in schizophrenia?

  Genes lead to biological differences affecting dopamine and brain structure
• What is the risk of developing schizophrenia for individuals with affected family members?

  Higher than for those without affected family members
• What relationship exists between genetic similarity and schizophrenia risk?

  Stronger genetic similarity increases shared risk
• What did Gottesman's (1991) study find about schizophrenia rates in the general population?

  The rate is 1%
• What is the likelihood of a child developing schizophrenia if one parent has it?

  13% likelihood
• How does the likelihood of developing schizophrenia change if both parents have it?

  Increases to 46%
• What did Tsuang et al. (1990) estimate about first-degree relatives of schizophrenics?

  5-20 times higher risk of developing schizophrenia
• What do twin studies indicate about schizophrenia's heritability?

  Higher concordance in MZ twins indicates heritability
• What is the concordance rate for MZ twins if one twin has schizophrenia?

  48% risk for the other twin
• What is the concordance rate for DZ twins if one twin has schizophrenia?

  17% risk for the other twin
• What does the research suggest about the genetic nature of schizophrenia?

  It is polygenic and aetiologically heterogeneous
• How many genetic variations did Ripke et al. find associated with schizophrenia risk?

  108 separate genetic variations
• What role does the COMT gene play in schizophrenia?

  It regulates the production of dopamine
• What did Joseph (2004) find about MZ and DZ twin concordance rates?

  MZ twins had 40.4%, DZ twins had 7.4%
• What does the higher concordance rate for MZ twins suggest about schizophrenia?

  Genes influence the development of schizophrenia
• Why is the concordance rate for MZ twins not 100% significant?

  It suggests other factors are involved
• What percentage of people with schizophrenia have no relatives with the disorder?

  Two-thirds of people with schizophrenia
• What is a problem with the genetic argument regarding schizophrenia?

  Separating nature and nurture is difficult
• How might shared environments affect twin studies on schizophrenia?

  They could increase concordance rates irrespective of genes
• What could be a confounding variable in twin studies of schizophrenia?

  The shared environment before birth
• What is the role of neurotransmitters in schizophrenia?

  They influence brain function and behaviour
• What are neural correlates in the context of schizophrenia?

  Biological differences linked to the disorder
• Why is the polygenic nature of schizophrenia significant?

  It indicates multiple genes contribute to the disorder
• What does aetiological heterogeneity imply for schizophrenia?

  Different gene combinations can lead to the condition
• How do environmental factors impact schizophrenia development?

  They interact with genetic predispositions
• Why is it important to consider both genetic and environmental influences in mental health disorders?

  They both contribute to the disorder's complexity