Introduction Schizophrenia is a chronic mental health condition that can cause a range of psychological symptoms which include hallucinations and delusions. There is no exact cause of schizophrenia and no current cure yet it is one of the most common serious mental health conditions with one in one hundred people experiencing an episode of schizophrenia within their lifetime (Butcher, Hooley and Mineka 2014) Schizophrenia is a complex disorder with many possible causes that can predispose individuals to it or trigger it in them. The Mayo Clinic : “It's not known what causes schizophrenia, but researchers believe that a combination of genetics and environment contributes to development of the disorder.
Problems with certain naturally occurring brain chemicals, including neurotransmitters called dopamine and glutamate, also may contribute to schizophrenia. Neuroimaging studies show differences in the brain structure and central nervous system of people with schizophrenia. While researchers aren't certain about the significance of these changes, they support evidence that schizophrenia is a brain disease”.

Biological Causes; Genes, Environment, Biochemical, Drug Misuse Genetics S is influenced by genetics but not determined by it. Genetic factors can be researched using twin studies, especially those who have been reared apart (to try and prove whether environmental factors have an influence on schizophrenia using studies with adopted children or other cases.) and looking at the differences between monozygous and dyzygous twins. Evidence so far shows that concordance rates for schizophrenia in monozygous twins is much higher that the concordance rate for dizygous twins, providing support for genetic factors. I Relatives of schizophrenics are at a significantly higher risk for schizophrenia. Eg: Children of a schizophrenic parent: 9-16%, Children of 2 affected parents: 40-68%, Gottesman found monozygotic twins have a concordance rate of 48%, whilst dizygotic twins have a concordance rate of 17%. However, if schizophrenia was purely a genetically transmitted disorder, than the numbers for identical twins should be 100%. They never are, so there must be other causes as well. Nevertheless, twin studies and adoption studies consistently indicate a genetic component to schizophrenia (Gottesman, Mcguffin & Farmer, 1987). These studies establish two things very firmly: that genes do have some role in at least some types of schizophrenia, and that genes are not the whole story in schizophrenia http://ccvillage.buffalo.edu/Abpsy/lecture14.html MRI
MRI has become the method of choice for exploring the pathophysiology and the psychopathology of schizophrenia, because of its high contrast sensitivity and spatial resolution, in the absence of radiation exposure. This is particularly important in research studies involving children and adolescents (BRAMBILLA & TANSELLA, 2007)
Brain dysfunction
Using brain imaging techniques, such as P.E.T scans, researchers have found many schizophrenics have enlarged ventricles, on average 15% larger than normal. Some psychologists believe that the increase in the size of these ventricles is what leads to the schizophrenic symptoms.
The brain imaging scans support this explanation in itself, it’s clear that a lot of schizophrenics have different brain structures to normal people, so there must be some correlation between the two.
Research by Meyer-Lindenberg (2002) found that reduced activity of the prefrontal cortex is linked to dopamine abnormalities. This could provide an explanation of why brain dysfunction could cause schizophrenia, not show a correlation.
Viral Infections
Viral Infection
Some researchers suggest that brain abnormalities that lead to schizophrenia could be caused by viral infection. For example, contracting diseases such as Flu or Syphilis in the womb may relate to developing schizophrenia in later life.
Evaluation of Viral Theory
Torrey (2000) found that more schizophrenics are born in the winter, when it is cold and exposure to viruses is higher, than in other months. Although this link is only correlational it suggests viruses do affect the chance of developing schizophrenia.
Environmental Causes of S
Twin and adoption studies suggest that inherited genes make a person vulnerable to schizophrenia and then environmental factors act on this vulnerability to trigger the disorder.
As for the environmental factors involved, more and more research is pointing to stress, either during pregnancy or at a later stage of development. High levels of stress are believed to trigger schizophrenia by increasing the body’s production of the hormone cortisol.
Research points to several stress-inducing environmental factors that may be involved in schizophrenia, including: * Prenatal exposure to a viral infection * Low oxygen levels during birth (from prolonged labor or premature birth) * Exposure to a virus during infancy * Early parental loss or separation * Physical or sexual abuse in childhood