Biological explanations of schizophrenia

• The first biological explanation of schizophrenia - genetic theory?

  The genetic theory does not suggest that schizophrenia is a single gene but a polygenic whether there's a number of genes which are responsible for the disorder. twin studies MZ twins are predominantly used as they share 100% of the same genes which makes it more reliable when establishing whether there is a link with genetics
• Gottesman's research into the coordinate study- for the genetic theory?

  • He argues that the closer The genetic relationship you are with someone who has schizophrenia the greater chance that the family members will also be diagnosed with the condition.
  • if a family member like a brother or sister has the diagnosis there's a 9% their sibling would also be diagnosed with it.
  • if one DZ twin, there are 17% of the other twin will be diagnosed with schizophrenia.
  • MZ twin has it there is a 48% the other twin will be diagnosed with schizophrenia.
• however there is constraints with Gottesman's study what is it?

  • with studies which use a Longitudinal design and following participants forward is that the diagnosis criteria for schizophrenia changes over time.
  • As a consequence it is difficult to compare the same symptoms in parents and their offspring which Can distort the coordinates rates this weken the validity of the study as we cannot be sure that accurate comparisons Has been made this limiting the support for the biological explanation
• what is the biological explanation of the dopamine hypothesis for schizophrenia?

  • Hyperdopaminergia in the sub-cortex is the dopamine hypothesis. It states that there are high levels of dopamine active in the central areas of the brain E.g expressive levels of dopamine in the Broca's area which is responsible for speech can explain poverty of speech.
• what is the biological explanation of the dopamine hypothesis for schizophrenia?

  Hyperdopaminergia in the cortex is the reversed version and states that there are low levels of dopamine activity in the brains cortex. low levels of dopamine in the prefrontal cortex areas involving thinking and decision-making can explain negative symptoms
• what is the biological explanation of schizophrenia using the neural correlates?

  Patterns of structure or activity in the brain that occurs in concurrence with an experience (Schizophrenia)
• what is the neutral correlates with negative symptoms of schizophrenia?

  abolition in the loss of motivation the ventral striatum is believed to control this function. Studies have shown and negative correlation with activity levels in the ventral striatum and motivation
• what is the neutral correlates with positive symptoms of schizophrenia?

  PET scans have shown patience experience auditory hallucinations are linked with low activation levels in the temporal lobe
• evaluating biological explanations of schizophrenia?

  • evidence for the dopamine hypothesis. Yes, dopamine agonists like amphetamines worsen schizophrenia and cause schizophrenia like symptoms in non-schizophrenic suffers. Antipsychotics reduce levels of dopamine.
  • Ripke found genes coding for other neurotransmitters like glutamate.
• evaluating biological explanations of schizophrenia?

  The correlation/causation issue. Low levels of activity in VS assume to cause abolition or Symptoms cause less information to travel to VS. A third Factor could affect both the VS symptoms, Neural correlates Nothing about the origins of the disorder
• evaluating biological explanations of schizophrenia?

  • evidence for genetics acceptability. Gottesman's Research.

  Tienari Found children from schizophrenic parents adopted by non-schizophrenic families are still at an increased risk of developing it Meaning that is genetic vulnerability.

  Ripke's genome Study shows genetics are involved