Genetics

• what is the genetic explanation of schizophrenia based on?

  Schizophrenia is inherited
• what is the risk of developing schizophrenia in your lifetime?

  less than 1%
• What was hypothesised about genetic mutation and schizophrenia?

  genetic mutation is responsible for the neurochemical imbalances in people with schizophrenia
• What is the COMT gene responsible for?

  gives instructions for the creation of enzymes that break down neurotransmitters like dopamine.
• what happens if the COMT gene is deleted?

  dopamine is poorly regulated which leads to schizophrenia symptoms
• What is the role of the DISC 1 gene?

  codes the creation of GABA which regulates dopamine
• if there is an abnormality in the DISC 1 gene, what happens?

  people are 4 times more likely to develop schizophrenia.
• What did Gottesman find in support of the genetic explanation?

  there is a genetic influence in schizophrenia, particularly in twins.

  MZ twins = 48% concordance rate

  DZ twins = 17% concordance rate
• what is a weakness with Gottesman’s study?

  there must be other influences otherwise the concordance rates with MZ twins would be 100%
• What was found in family and twin studies that supports the genetic explanation of schizophrenia?

  the risk of schizophrenia increases with genetic similarity.
• what is a weakness of family and twin studies?

  they ignore environmental impacts on the development of schizophrenia
• What is a weakness of the genetic explanation?

  schizophrenia can occur with no family history because the genetic mutation can be spontaneous.