Biological explanations

• Evaluate the biological explanations of sz: genetic basis (+) strong evidence to support vulnerability and link to sz

  findings of the following researchers (Gottesman, Tiernari, Ripke). There is overwhelming evidence for the idea that genetic factors make some people more vulnerable to developing sz than others. This doesn't mean that sz is entirely genetic, but the evidence suggests that genetic susceptibility is very important.
• Evaluate the biological explanations of sz: genetic basis (+) supported by the role of mutation


  sz can happen even when there is no family history to it. this could be caused by a mutation in parental DNA which could be caused by radiation, viral infection or poison. evidence for this comes from a study showing a positive correlation between paternal age + risk of sz, inc from around 0.7% with father under 25 and 2% in father over 50.
• Evaluate the biological explanations of sz: dopamine hypothesis (-) mixed evidence in support - studies supporting


  found: dopamine agonists like amphetamines that inc levels of dopamine make sz worse + can produce schizophrenia-like symptoms in non-sufferers, Antipsychotic drugs OTOH work by reducing dopamine. Both suggest important role for dopamine in sz. Radioactive labelling studies show chemicals needed to produce dopamine are taken up faster in the brains of sz sufferers than controls, suggesting that they produce more dopamine.
• Evaluate the bio explanation of sz: dopamine hypothesis (-) mixed evidence in support - non-supporting evidence and E 


  suggest that dopamine does not provide a complete explanation for sz. Some of the genes identified in the Ripke study code for the production of other neurotransmitters, so it appears that other neurotransmitters along with dopamine are important factors in sz. Attention in current research has shifted to the role of a neurotransmitter called glutamate. evidence for dopamine hypothesis = mixed - can't be considered as an accurate explanation.
• Evaluate the bio explanation of sz: neural correlates (-) correlation-causation problem


  studies such as Juckels (found a negative correlation between activity levels in ventral striatum and negative symptoms) are useful in flagging up particular brain systems that may not be working normally, this kind of evidence leaves the question, is it the brain activity causing sz or the other way around? for e.g also a possibility that sz is causing less activity in the VS. there could also be a 3rd factor that influences both the VS and the negative the symptoms. (give E)There