Biological Explanation to Schizophrenia Essay

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June 2013 Full Mark Example: Discuss biological explanations of schizophrenia (8+16 marks) One biological explanation of sz is the idea of genetics. This is that sz is actually a genetic disorder as it has been passed down through genes, it’s heredity. One piece of evidence which supports this is the fact that prevalence of sz is the same around the world at 1%. This would suggest that it is biological as it doesn’t vary with the environment. However there have been geographical variations as Torrey found that the prevalence of Sz was 4% in Ireland whereas it is very low in parts of Africa. This may be due to the poorer medically educated culture though. The way sz is studied in genetics is through twin studies and looking at concordance rate and also family studies. One study loooked at the concordance rate of sz in twins. The study consisted of 210 MZ and 319 DZ twins. The findings were that in MZ twins the prevalence rate was 35-58%. Whereas it was only 9-26% in DZ twins. This evidence does support the genetic explanation for Sz but it is not conclusive because MZ share 100% genetics you would expect it sz was completely biological that it would be 100% concordance. However the study find in more severe cases of sz a concordance rate of 75-91% in MZ twins. This does make the genetic explanation stronger for sz but it isn’t 100% suggesting that there must also be other factors which affect it. This study used a large sample size as it was a meta analysis using 5 studies this makes the explanation more credible when generalising the explanation to other schizophrenics. However there are issues when using twin studies, MZ twins not only share 100% genetics but it is very likely that they share a very similar environment. This weakens the use of twin studies because concordance rate may be so high due to environmental factors. Also as the study was a meta
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