1999 First Web Reports
Change in View: Schizophrenia Moves From Psychology to Biology
Early on in the research regarding the disease schizophrenia, it was thought by doctors to be an illness of a psychological nature, not one relating to the brain. However, in the context of "Neurobiology and Behavior," and in recent light of new information about the disease, I will be examining it as a product of the brain, one that most now believe originates in early childhood. Not only that, but the evidence for it being a biological function of the brain also lies in genetics, with some startling statistics on the signs of the disease.
What is Schizophrenia?
In order to understand the entire paper, it is extremely necessary to cover the basic facts as to what schizophrenia is in patients. Schizophrenia, now seen as an illness of the brain, has been around as early as recorded history. For the longest time, however, people were seen as crazy and either tried as witches or condemned by society as lunatics. It was not until the rise of psychology that the disease was seen as a mental illness. Today, even more importantly, is the understanding that schizophrenia is a fairly common disease and drug treatments have been developed to help patients with symptoms. Approximately 1-1.5% of the population are diagnosed with it sometime throughout there lives, but I will get to general ages and percentages later on in general information. The disease itself has several key characteristics for diagnosis. Here is a short list of some of the symptoms:
1. Grossly abnormal behavior in terms of thought
Essentially, to translate the above statements, 1: The thoughts of someone with schizophrenia are not clear or logical any longer. Outward symptoms include disconnected or incomprehensible language. This leaves people with schizophrenia unable to socially participate in conversations and can make it hard for them to stay close to family and friends. 2: Delusions frequently occur in people with schizophrenia and cause individuals to often feel like they are being conspired against. Finally, 3: Hallucinations tend to come in the form of voices, but can also be felt as well as heard. The voices tend to tell the victims of the disease what they must do. There can also be multiple voices carrying on conversations.
Time of Affliction
Like most illnesses, schizophrenia has a very definite time window that it tends to emerge. This is a direct quote from the schizophrenia homepage, reference 1, "Three-quarters of persons with schizophrenia develop the disease between 16 and 25 years of age. -- Onset is uncommon after age 30, and rare after age 40." As far as statistics go, 1-1.5% of the general population, as stated above, are susceptible. If one parent of a child has schizophrenia, the percent likelihood rises to 13%. If both parents have schizophrenia, the chance of an offspring having the illness is 35%.
Although this short introduction is obviously not enough to understand all the nuances of schizophrenia, I wanted to whet your appetite for the main topic, that being new evidence that schizophrenia emerges in the fetal brain. All general facts listed above can be found at reference 1, the schizophrenia homepage at www.schizophrenia.com.
Schizophrenia in the fetal brain?
Not too long ago in medical history, evidence was gathered that pointed to a new possibility in the cause of schizophrenia: a heavily biological basis that originates in the fetus. Apparently a receptor in the brain that responds to acetylcholine does not work as well in the brain of schizophrenics. This lack of neurotransmitter in the body makes it so the brain does not function properly. The acetylcholine normally reports to the hippocampus, the center of processing information in the brain. It was previously believed that the biological problems were found on a total of five chromosomes, but they feel they have limited the problem to a specific gene or two. It is then important to look to the mother, to see what might have caused her to pass on the problem during her pregnancy.
Therefore, the environmental trigger that is said to cause this biological deficit is "a viral infection during the second trimester of pregnancy and Rh-incompatibility between the mother and the infant" 2. Essentially, what occurs within the fetus is that the neurons do not develop properly, causing schizophrenics to have disorganized thoughts and problems with mental functioning. Another study believes firmly that there are indeed five chromosomes involved in the deficit leading to schizophrenia, but that chromosomes 22 and 6 play the biggest role. There is also some evidence that in prenatal development, the fetus not getting enough oxygen could contribute to the problems seen in schizophrenics 6.
Biological changes during child development
Further evidence that schizophrenia is biological in nature as opposed to something of the mind is what physically happens to people with the disease as they approach age 14-16. By doing an MRI on teenagers who might show signs of illness, there is an enlarging of the ventricles that becomes greater as the child progresses in age. This kind of enlargement, too, is seen in the brain of schizophrenics versus non-schizophrenics. In addition, there were abnormalities in the autonomic nervous system of these young adults that matched that of schizophrenia in older adults. These changes can be seen through external behaviors, such as "developmental disturbances, such as lags in motor and speech development." 3.
Yet another view of schizophrenia and it's origins comes from a different part of the brain, or perhaps an add-on to the above information. Some of the definite symptoms of the schizophrenia are seen as metabolic brain changes in patterns and activities, as well as "over-perfusion of blood, others to under-perfusion." 4 More specifically, some controversy arises as to whether or not the disease is actually just one problem in the brain, or several problems. There is also a dopamine theory of schizophrenia, in which it is believed there are problems with dopamine receptors in the brain. This, in turn, is thought to be part of the total picture of biological brain functioning problems in schizophrenia. 5.
Real World Implications
The rise of schizophrenia, obviously biological in nature, can at least now be identified and treated. My interest in the topic was one relating to brain and behavior. Patients that were once thought to have a mental disorder are now seen as having a disease/illness of a biological nature. This, I believe, shows that certain behaviors (schizophrenia in this case) can in fact be linked back to the brain in relation to outward or inner behavior. Psychology does play an appropriate role in support for these illnesses, but the behavior is no longer something mystical in origin, but pinpointed to a specific genetic or fetal factor. Perhaps, then, a final point to ponder is that the question raised in this course of brain=behavior will show itself to be true as more discoveries, like the one of schizophrenia being biological in nature, are made.
WWW References to Schizophrenia
1)Schizophrenia Home Page
2)Brain Genes and Schizophrenia
3)Brain Change in Childhood Schizophrenia
4)In Depth Brain Research on Schizophrenics
5)Dopamine Role in Schizophrenia
6)Chromosomes and Their Clues to Schizophrenia