Two Biological Explanations of Schizophrenia Essay
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Two Biological Explanations of Schizophrenia
There are many biological explanations of schizophrenia. In this essay I will concentrate on the genetic explanation and biochemical explanation of the disorder. There are many studies that look in to genetics and the link to schizophrenia. This is dues to an original finding that schizophrenia runs in families and therefore suggests that genes are responsible for the disorder. I study was preformed by Janicak et al 2001; they found that monozygotic twins have a 48% concordance rate. This is considerably less in dizygotic twins where the concordance rate falls to 17%. This would suggest there is a strong case for genetics being involved with…show more content…
Gottesman also supports the genetic link, showing schizophrenia is more common in close biological relatives of a schizophrenic. However genetic explanations cannot account for the patients who have no family history of the disorder.
Biochemical factors are used to suggest that schizophrenia is caused by abnormal neurotransmitter activity. The main aspect of this explanation is the Dopamine hypothesis. Schizophrenia has been linked to with high levels of dopamine in the brain. Dopamine is a neurotransmitter associated with attention. Schizophrenics seem to have an increased number of D2 dopamine receptors on receiving neurons. This theory is support by the fact that Phenothiazines bind with D2 receptors and reduce positive symptoms. Another piece of supporting evidence is that Parkinson’s disease drug L-dopa, increase the level of dopamine and causes schizophrenic like symptoms in some people. However excess dopamine can only explain some types of schizophrenia, usually positive rather than negative. Newer antipsychotic also affect levels of other neurotransmitters. This theory can also not explain why some schizophrenics have long periods of remission.
(a) Outline and evaluate two non-biological explanations of schizophrenia
People diagnosed with schizophrenia come from all types of social backgrounds, but most are clustered
Outline and evaluate two or more biological explanations for schizophrenia
similar environments. Even when the adopted environments are similar, there is still the shared experience in the womb and at birth so pre-natal viruses or birth trauma may have had an effect. Overall the evidence suggests that genes play a part but nature cannot completely explain schizophrenia as there is not a 100% concordance rate. Nurture needs to be considered and the evidence suggests environmental factors must play a part.
Without knowing the specific genes involved we can’t
explain how these contribute to the development of schizophrenia, however the current advances in research into the mapping of genes may bring more insight to the process. Schizophrenia has also been explained by brain chemistry. There are certain chemical abnormalities that can be observed to produce schizophrenia-like states. For example, prolonged use of LCD or ant abuse which is a drug used for alcoholism. Genetics may have an effect through body chemistry. The original dopamine hypothesis suggested that schizophrenia is associated with an excess of the neurotransmitter dopamine causing neurones to fire too often and transmit too many messages. A more recent version says that rather than an excess of dopamine it is an excess of dopamine receptor cells (D2 receptors) that lead to more firing and excess messages. Dopamine neurones play a key role in guiding attention so disturbances in this process may lead to the problems of attention and thought found in people with schizophrenia. Antipsychotic drugs block the activity of dopamine in the brain and eliminate symptoms such as hallucinations and delusions (they are used to treat many schizophrenics); therefore this provides strong evidence for dopamine being a significant contributory factor for schizophrenia. It reinforces the fact that there may well be a causal relationship between dopamine message overload and schizophrenia. However, not all schizophrenic patients respond to these drugs. L DOPA is
a drug used to treat Parkinson’s di
sease. It increases dopamine levels. It