Biological explanations for schizophrenia

• What is the focus of lesson two on schizophrenia?

  Biological explanations for schizophrenia
• What two factors are included in the biological explanations for schizophrenia?

  Genetics and neural correlates
• What type of studies do biological psychologists use to investigate genetics?

  Family, twin, and adoption studies
• What do family studies in schizophrenia investigate?

  Biological relatives' occurrence of schizophrenia
• What did Gotham's man find in 1991 regarding schizophrenia?

  More common among biological relatives
• How do twin studies contribute to understanding schizophrenia?

  By comparing identical and non-identical twins
• What indicates a genetic cause in twin studies?

  Higher concordance rate in identical twins
• What do adoption studies reveal about schizophrenia?

  Impact of genetics in separated individuals
• What is the concordance rate for monozygotic twins regarding schizophrenia?

  40 percent
• What percentage of adoptees with schizophrenic mothers receive a diagnosis?

  6.5 percent
• What is a limitation regarding concordance rates in schizophrenia studies?

  They do not exceed 50 percent
• What does the original dopamine hypothesis suggest?

  Excess dopaminergic activity causes schizophrenia
• What is the relationship between dopamine and positive symptoms of schizophrenia?

  Excess dopamine activity leads to positive symptoms
• What happens when there is an increase of activity in the auditory cortex?

  It can lead to auditory hallucinations
• What did Davis suggest about dopaminergic activity in 1991?

  Abnormal levels, not just excess, are important
• What can too much dopamine in the mesolimbic pathway cause?

  Positive symptoms of schizophrenia
• What can a deficit of dopaminergic activity in the prefrontal cortex lead to?

  Negative symptoms like cognitive impairment
• What are the evaluation points for the role of genes in schizophrenia?

  • Research support from family, twin, and adoption studies
  • Ripke et al. found 108 gene variations linked to risk
• What are the limitations of genetic explanations for schizophrenia?

  • Environmental factors also increase risk
  • Biological and psychological influences are often ignored
• What supports the dopamine hypothesis?

  • Dopamine agonists worsen symptoms
  • Antipsychotic drugs reduce dopamine activity
  • Candidate genes affect dopamine production
• What is a limitation of the dopamine hypothesis?

  • Evidence for glutamate's central role
  • Raised glutamate levels found in schizophrenia
• What types of exam questions could arise from this topic?

  Outline and evaluate various hypotheses
• What is a potential essay question regarding the dopamine hypothesis?

  Outline and evaluate the dopamine hypothesis
• How can the biological reductionism point be applied to the dopamine hypothesis?

  By linking genetic factors to dopamine activity
• what do family studies do

  find individuals with schizophrenia and determine whether their biological relatives are similarly affected.
• in family studies what did gottesman (1991) find

  children with 2 schizophrenic parents had concordance rate of 46% and 1 had 13%
• what did twin studies find

  if mz twins are more concordant than dz twins the similarity is due to genes
• in twin studies what did the meta analysis find

  found a concordance rate of 40% for mz twins and 7% for dz twins
• what were adoption studies

  studies of genetically related individuals who have been reared separately.
• what are neural correlates

  structures or patterns of activity in the brain that correlate with the occurence of a symptom
• what is the name of the key neural correlate

  dopamine hypothesis
• what did further research on the dopamine hypothesis suggest

  1.schizoprenics have excess levels of dopamine receptors on receiving neurons

  2.so more dopamine binding

  3.and more neurons firing
• who identified the revised dopamine hypotheis

  davis et al 1991
• what did davis et al find

  1.too much dopamine in mesolimbic pathway can lead to positive symptoms

  2.deficit of dopamine in the pre frontal cortex leads to negative symptoms