Genetic

• Schizophrenia runs in families and is in part genetic - inherited through DNA
• Schizophrenia is polygenic (different combinations of genes can lead to the condition)

  • 108 genetic variations associated with increased risk of SCZ
• Linked to mutation in the PCM1 gene - leading to defective cillia in the brain
• Genes lead to changes in dopamine/structural changes in the brain
• Gottesman (1991)

  Identical twins share 100% genetics (monozygotic)

  • Concordance rates = 48%

  Non-identical twins share 50% genetics (Dizygotic)

  • Concordance rates = 17%
• Hard to untangle genetic and environmental influences for individuals who share genes and environment. So, researchers use studies of genetically related individuals who have been reared apart
• Tienari et al (2000) - Adoption study 


  Studied 164 adoptees whose biological mothers had been diagnosed with SCZ and 197 control adoptees whose mothers hadn’t been diagnosed with SCZ

  • 11 adoptees were diagnosed with schizophrenia (about 7%)
  • 4 adoptees from the control group developed SCZ (about 2%)