biological explanations

• neural correlates

  -structures in the brain/things that happen in the brain that relate to an experience or may be the cause/origin of the experience
• dopamine

  -neurotransmitter linked to pleasure; reward; motivation etc
• genetic counselling

  -support offered to people who have a predisposition of a genetic disorder
• genetic basis of schizophrenia (Gottesman)


  -SCZ is inherited through genes

  -Gottesman (1991): family study on the risk of developing SCZ. Monozygotic twins = 48% likely to both have SCZ; dizygotic twins = 17% likely to both have SCZ; 2nd degree relatives = 4% likely to both have SCZ; general population = 1% likely to both have SCZ. Higher concordance rates when genetics are more similar.
• genetic basis of schizophrenia (polygenic & aetiologically heterogenous)

  -there are candidate genes involved in SCZ, mostly genes that code for dopamine

  -SCZ is polygenic (more than one gene)

  -aetiologically heterogenous: there are different combinations of genes that cause SCZ

  -Ripke et al (2014): meta-analysis of studies into genomes. Found 108 gene variations associated with the risk of SCZ. Shows it is polygenic & aetiologically heterogenous

  -most common candidate gene codes for dopamine
• genetic basis of schizophrenia (gene mutation)

  -SCZ isn't just caused by a biological predisposition, it can be caused by gene mutation

  -mutation happens in many ways e.g., exposure to viral infections

  -Brown et al (2002): the older fathers are, the more likely children are to have schizophrenia (shows gene mutation)
• neural correlates basis of schizophrenia

  -dopamine hypothesis: past SCZ treatments (early antipsychotics) found that dopamine links to SCZ

  -hyperdopaminergia: high levels of dopamine in the subcortical regions (in broca's area) are linked to positive symptoms e.g., hallucinations

  -hypodopaminergia: low levels of dopamine in the cortical areas (prefrontal cortex) are linked to negative symptoms e.g., avolition

  -abnormal levels of dopamine are linked to genetic variations (and early experiences)
• genetic basis of schizophrenia - AO3

  Strength(s):

  -supporting research: Tienari et al (2004): 19k adoptive children, bio mother = SCZ. These children have an increased risk of SCZ even if they grew up in a different environment. D: large sample, increases generalisability. Increases the validity of genetic explanation.

  -research found higher concordance rates in MZ than DZ. increases the validity.

  
  

  Weakness(es):

  -contradictory evidence: evidence to say that SCZ is caused by more than genes e.g., smoking THC-rich cannabis throughout teenage years. Decreases the validity, is reductionist.

  -alternative explanation: childhood trauma. 67% of people with SCZ reported having childhood trauma. Genetic explanation is reductionist as only considers genes.