• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Discuss the genetic and biochemical explanations of schizophrenia

Extracts from this document...

Introduction

Discuss the genetic and biochemical explanations of schizophrenia (25 marks) Biological explanations have been used in attempting to explain many mental disorders. However, such explanations have proved more successful in accounting for the development of schizophrenia than most other disorders. Two main branches of this type of explanation are genetic factors, which explain schizophrenia through inheritance of abnormal genes; and biochemical factors, which explain schizophrenia through the presence of abnormal neurochemicals. Nonetheless, there is contrasting evidence for both and it has been suggested that you can't completely separate these explanations from each other as schizophrenia is a complex and multi-cause disorder. In order to use twin studies to support genetic explanations of schizophrenia, when one twin is known to be schizophrenic, researchers are interested in the probability that the other twin may also be. This is known as concordance. Gottesman (1991) summarised 40 twin studies and found that the concordance rate was 48% when a monozygotic or identical twin had schizophrenia, but only 17% when a dizygotic twin or non-identical twin had schizophrenia. ...read more.

Middle

Despite large differences in concordance rates reported across twin studies and disagreements of their validity, two findings have been obtained repeatedly: identical and fraternal twins who have a co-twin with schizophrenia are much more likely than random members of the population to suffer from the disorder, and; among twins having a co-twin with schizophrenia, identical twins are at significantly greater risk than fraternal twins. This undoubtedly suggests that genetic factors play a significant part in the explanation of schizophrenia. Although, it may be better to consider environmental factors also. This can be seen in the study of adopted children. Tienari (1991) compared 155 adopted children who had a schizophrenic parent with 155 adopted children who did not have a schizophrenic parent. In all, 10.3% of those children with schizophrenic mothers developed the disorder, compared to only 1.1% of children without schizophrenic parent. Wahlberg et al. (1997) reported additional findings from this study, showing that environmental factors are also important. They found that children at genetic risk due to schizophrenic mothers had very good psychological health if raised by adopted families low in communication deviance (tendency to communicate in unclear and confusing ways). ...read more.

Conclusion

There is also more direct evidence based on post-mortem studies of schizophrenic patients. These showed that such patients had a greater density of dopamine receptors in certain parts of the brain than individuals not suffering from the disorder. There are, however, several problems relating to the dopamine hypothesis. Firstly, it is hard to assess brain levels of dopamine in patients with schizophrenia, this can only be done in a direct way by post-mortem assessment. It is also possible to assess dopamine in an indirect way. However this involves inserting a needle into the spine, which can be dangerous. The findings have generally been negative - patients with schizophrenia do not seem to produce more dopamine than other people. In conclusion, dopamine is probably of importance in understanding schizophrenia. However, it looks increasingly as if there are various complex differences in dopamine functioning between those with schizophrenia and healthy individuals. There is also the causality issue. If we find an association between having schizophrenia and having high levels of dopamine, the excessive dopamine levels might have played a part in causing the schizophrenia. However, it is also possible that elevated dopamine levels are in part a consequence of having schizophrenia. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Physiological Psychology section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related AS and A Level Physiological Psychology essays

  1. Outline Clinical Characteristics of Schizophrenia and discuss psychological explanations of Schizophrenia

    There are said to be problems as it is called a retrospective recall, as the data is unreliable. For example, delusions may occur meaning that the patients are recalling things that didn't happen. Another criticism of the Double Bind theory is the inability to replicate the findings across studies.

  2. Depression - Gender Differences.

    Astrocytic responsibility includes maintaining the blood brain barrier (BBB), as well as providing structural support, protection and repair of the central nervous system (CNS). Neurons, on the other hand, are the vital links between electrical impulses and the nervous system.

  1. Stress in the Workplace : Why Is it Important to Deal with It?

    And fight or flight reflects your body's stress reaction. When you feel stress, you are feeling the effects of your body's preparation to cope - your body becomes motivated and energised so that it can maintain control - to fight something or run away. Of course this chap down here doesn't look as though he has much choice - but who saw the Edge on Sunday night ?

  2. Marked Essay - Discuss biological explanations of schizophrenia.

    // Autopsies have also found that people with schizophrenia have a more than usual amount of dopamine receptors ? a Falkai et al 1988. Curran et al concluded that effects of taking illegal stimulant drugs were similar to that of schizophrenia.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work