Biological explanations for SZ

• What are Genetics as a biological explanation of Bio explanations of SZ

  Sz is hereditar, vulnerability increases with genetic similarity. Candidate genes are genes that increase likelihood of SZ, polygenic so its multiple genes and aeteologically heterogeneous so different combinations increase likelihood. Ripke Found 108 genetic combinations that increase risk
• Strength of genetics as a bio explanation of SZ

  Adoption studies: adopted child is genetically related but diff environment, found if mother has SZ child had 6.7% chance of development but if mother no SZ child is 2% at risk > shows there is generic component and allows for environmental factor to be ignored
• Weakness of genetics as a biological explanation of SZ

  Methodological limitations of twin studies > concordance rates not 100% so SZ is not fully genetic cause, identical twins have similar environments
• Dopamine hypothesis as a biological explanation for SZ

  Neurotransmitter involved in reward, SZ patients have different levels of dopamin. hyperdopaminergia is too much dopamine, in brocas area can lead to Speech poverty. Hypodopaminergia is too little dopamine, in prefrontal cortex can lead to avolition
• Weakness of dopamine hypothesis as a biological explanation of SZ

  Alternative explanation> other neurotransmitters involved such as glutamate, new antipsychotics now regulate glutamine and dopamine and have increased effectiveness
• strength of dopamine hypothesis as a biological explanation of SZ

  Research support: dopamine agonists (amphetamines) increase activity and hallucinations in non SZ people, dopamine antagonists (anti psychotics) decrease activity to treat patients
• Neural correlates as a bio explanation for SZ

  Links between structure + activity in brain with SZ symptoms, superior temporal gyrus has role in language processing > low activity here meant auditory hallucinations. Ventral striatum has role in anticipation of reward > low activity here meant avolition
• Weakness of neural correlates as a biological explanation of SZ

  Correlation causation issue > unclear if low activity causes symptoms or symptoms cause low activity, could be another variable causing correlation