bio explanation

define polygenetic in terms of schizophrenia

this is the ideas that many gene increase your risk / are associated with schizophrenia

name some genes thought to be related to schizophrenia

Specific genes (e.g., COMT, DISC1)

aetiologically heterogeneous

different combination of genes cause schizophrenia in different people

how do family study help prove the schizophrenia is genetic

If its genetic then the more DNA they share in common the higher the concordance rates

One strength of the genetic explanation is evidence in support

Gottesman reviewed cases of schizophrenia in families and found a concordance rate of 17 % for Dizygotic twins (share 50% DNA) and 48% between monozygotic (share 100%) this is significantly higher than the percentage of general population which is 1%. This clear shows that schizophrenia has a genetic aspect to it both Dz and Mz twins share very similar environments yet there is such a big difference in concordance rate this point to the explanation being genetic. However cant solely be genetic as concordance rate isn’t 100%

what is a neural correlate

A neural correlate refers to a biological structure or function in the brain that shows a consistent relationship with the presence, experience, or severity of symptoms of a mental disorder — in this case, schizophrenia.

Describe the dopamine hypothesis

Symptoms of schizophrenia are associated with too much or an imbalance of the dopamine neurotransmitter across the brain. The exact mechanism isn’t certain but excessive amounts of dopamine (hyperdopamingeria remember like hyper to much energy ) in speech centres like broca’s area may lead to auditory hallucinations. Low levels (hypodopaminergia) in areas like the frontal cortex are thought to lead to negative symptoms like avolition or speech poverty.

How was the dopamine hypothesis discovered

By observing the effects of healthy people who had taken dopamine releasing drugs such as L dopa had schizophrenic like symptoms in patients. And those who had taken drugs which lowered levels of dopamine.

what other neurone transmitters thought to be involved

Glutamate linked to learning and attention and memory found in low quantities of patients and Serotonin

One strength if the dopamine hypothesis

Leueht et al conducted a meta analysis review of 212 studies these assessed the effectiveness of the biological antipsychotic drug treatment that work vias normalising the levels of dopamine. Results demonstrated these drug treatments were more effective than placebo. The effectiveness of treatments that influence the  dopamine system suggest that the underling cause is dopamine otherwise the drugs wouldn’t be effective. 

what is one limitation as the bio explanation as a hole

One limitation is that its overly reductions it fails to consider any other factors in the development of schizophrenia such as the environment. While gottesman found that genetic are related to schiophrenia Monozygotic twin only had a concordance rate of 48% if it was purely genetic then it would be 100. Therefore the diatheses stress may be a better explanation. It agrees that some people have a genetic vulnerability however the disorder needs a stressor an environmental factor such as traumatic event to trigger the condition. This is a more holistic approach considering both biological and environmental cause