Schizophrenia - A Disease of Risks

Schizophrenia is a disease that has played a significant role throughout my life. One of my uncles was diagnosed with schizophrenia when he was in college. The cause for the onset of the disease was always shrouded in mystery, however. If anyone in my family was asked why he developed schizophrenia or if there were signs of schizophrenia in him when he was younger, you would receive a different answer from each person. For this reason I always wanted to know what caused schizophrenia and why it is not always evident early on in a persons life.

When I began to research, the debates regarding schizophrenia centered around three main areas: dopamine production, genetics, and issues with neural development. In this paper I am going to focus on issues in early neural development, how neuron issues can cause schizophrenia, and why the symptoms of schizophrenia may not become evident until later in a persons life.

The first issue I would like to discuss in the paper is what causes the neurons to develop abnormally. The first main cause comes into play in genetics. Schizophrenia has been shown to be hereditable. Families with a member who has schizophrenia have a 10% greater chance of having another family member with schizophrenia and identical twins with schizophrenia in the family have between 50% and 85% of a chance of both having schizophrenia. (1,2) This genetic risk is one of the main risk factors that can lead to development of schizophrenia later on.

However, there are also other risk factors that can lead to the development of schizophrenia. There have also been shown to be environmental factors in the development of schizophrenia. Examples of environmental are ending of relationships or high amounts of stress. (2) These examples, however, normally occur later in a person’s life. These factors normally lead to the final onset of the schizophrenia, but are not the original cause. There are examples of environmental factors in a developing fetus. These examples include influenza, stress in the mother, or lack of RhD compatibility between mother and fetus. (1)

Genetics and environmental factors can lead to brain abnormalities, which are found in almost all people with schizophrenia. The question then becomes how and when do these factors cause the brain abnormalities that can eventually lead to schizophrenia. These questions do not have definite answers, however. The question that is answerable in some cases is the when. Studies have been done regarding influenza, stress and lack of RhD compatibility.

There have been many studies done regarding schizophrenia and influenza. In all cases, mothers who are both pregnant and have contracted influenza while pregnant have been studied. In all studies, mothers who contracted influenza during their first or third trimester have had children with normal rates for schizophrenia. However, mothers who have contracted influenza have contracted influenza during the second trimester have children who have much higher rates for developing schizophrenia. Studies have also been done regarding RhD compatibility. “The rates of schizophrenia were nearly three times greater when RhD-negative mothers gave birth to RhD-positive offspring, compared with those who were RhD compatible.” Schizophrenia due to RhD incompatibility also most commonly occurs in the second trimester. (1)

Stress on pregnant mothers also can cause schizophrenia in their children. These stresses can be many different things such as starvation or emotional stress. There is however something interesting that has to do with the timeline of schizophrenia developing. Many studies have been done regarding starvation. In all of these studies, however, schizophrenia is twice as likely in children whose mothers experienced it in their first trimester and not in children whose mothers experienced it in their second or third trimesters. (1)

Why starvation in the first trimester causes schizophrenia whereas influenza and RhD incompatibility in the second trimester causes schizophrenia is unknown. Starvation causes the fetus to not get enough nutrients which could cause neurons to die or not have the right nutrients to move to the correct areas. Influenza and RhD incompatibility however, affect the fetus much later. This could be because neurons still don’t have the ability to move to where they are supposed to or because neurotransmitter receptors are damaged. The reason, however, is not known and these are just my own speculations based on reading that I have done.

There is a point regarding schizophrenia that needs to be discussed before I talk about the abnormalities that are present in a schizophrenic’s brain, however. This point involves the difference is risk and onset. As is pointed out Michael Foster Green in Schizophrenia Revealed, risk factors are often present in children even while they are in the womb. These risk factors, however, do not mean that the child is definitely going to get schizophrenia. Instead, it is more an act of compiling the risk factors. If enough risk factors compile, then there may be an onset of schizophrenia. If enough don’t, the risk will remain, but there will be no onset. (1) I believe that this is an important point because it contributes to the fact that schizophrenia is very hard to pre-diagnose.

Abnormalities’ in the brain is an affect of the risk factors that I have discussed above. These abnormalities are also, in themselves a risk factor; they do not definitely lead to schizophrenia, but have the ability to. The abnormalities include a severe shrinking of brain size as well as a pointed concentration of neurons towards the middle of the brain. Also there are neurons that do not reach as far as they are supposed to. These neurons, then, do not make the proper connections and cannot act in the proper way. (1)

Schizophrenia is caused by a variety of risk factors that compile upon themselves. These risk factors can cause brain and neuron abnormalities or can cause brain and neuron abnormalities to become evident. Schizophrenia appears to be a disease of risks and the balance between too many risks or not. Schizophrenia can have its roots from many causes, but the outcome is always the same. \

List of Sources:
1) Green, Michael Foster. Schizophrenia Revealed: From Neurons to Social Interactions. New York: W.W. Norton & Company, 2001.
2) “Schizophrenia.” Mental Health Channel. 1998-2007. HealthCommunities.com, Inc. < http://www.mentalhealthchannel.net/schizophrenia/causes.shtml>.