Biological causes of abnormality

Genetic factors

Some people may inherit illnesses which have been carries on through genes passed down through generations. Davies (1985) found that relatives of schizophrenics are 19 times more likely to be diagnosed with the disease compared with people who do not have a trace schizophrenia in their family. Gene mapping includes identifying particular genes which causes an illness e.g. – Sherrington et al  (1988) found evidence that of a link between schizophrenia and a gene located on chromosome 5 although further research has been unable to confirm this.

Biochemistry

The patient’s bio chemistry is thought to cause abnormalities. For example – theorists argue that excessive amounts of a chemical known as dopamine is involved with schizophrenia, however this is only a correlation as so it is not certain whether this is a cause or an effect. There is also evidence that biochemical changes have affects on the symptoms of abnormality, for example it has been suggested that depression is associated with low levels of serotonin. Prozac increases serotonin activity therefore has been found to reduce the symptoms of depression.

Neuroanatomy

Neuroanatomy, the structure of the nervous system may cause abnormalities. Studies of schizophrenics have shown that their brains are different to those of non-schizophrenics, however whether schizophrenia caused the neuroanatomical changes or whether the differences were cause by schizophrenia is unknown.