Definition

Schizophrenia is a brain disorder that affects a person's ability to perceive the world and to process information. The word "schizophrenia" derives from the Greek, "schizo" meaning "split" and "phrenia" meaning mind. Thus, those diagnosed with schizophrenia often display flat or inappropriate affect, reflecting a splitting apart of normal emotions from responses, and a separation of thought and perceptual experiences from rational processes. This derivation misleads many into thinking schizophrenia is related to "multiple personality" like in the movies "The Three Faces of Eve" and "Sibyl". Multiple Personality Disorder, now known as Dissociative Identity Disorder, is one of the dissociative disorders and has nothing to do with schizophrenia.

Symptoms

The symptoms of schizophrenia tend to fall into four categories:

• People with schizophrenia may experience hallucinations. That is, they may hear or see things that are not there. Just as in a dream, where fantastic events can not be distinguished from real events, hallucinations can not be distinguished from real events. Thus, the hallucination of a voice talking is perceived in the brain just like a real person talking.
• Another symptom of schizophrenia is delusions, or false beliefs. These false beliefs may be very difficult for family or friends to understand, since they do not make sense. Again, a delusion seems as real to the person as a belief grounded in reality. This experience is also much like a dream experience. Just as in a dream, the reality of the dream situation, (for instance, that someone is plotting against one), seems very real. However, for the normal person, upon waking, it is clear that the plot was "just a dream". For the person with schizophrenia, the plot, or other delusion, continues to seem real.
• Other symptoms of schizophrenia may affect a person's ability to feel emotions--the abililty to be angry or happy may be dulled, or even gone. When this happens a person understandably will have decreased expression of emotions. In addition, a person with schizophrenia may have decreased motivation and become socially isolated, again understandable if nothing seems rewarding or very much fun.
• Finally, a person with schizophrenia may have disorganized speech or behavior; so that what they do or say does not make much sense.

Different people with schizophrenia may have any of these symptoms to varying degrees. In addition, the symptoms can be very mild, or very severe.

What is Wrong With The Brain in Persons With Schizophrenia?

In the last twenty years, there has been an explosion of knowledge about how the brain works. It is clear the brain functions in a highly integrated manner, and that there are neural circuits essential to normal brain function. These circuits are not unlike a very complicated road system, where information may travel down a main road, but may also get to the appropriate destination by alternative routes. Like the "alternative routes" that one may use in a traffic jam, the "alternative routes" may not be as efficient as the main route. Throughout life, but especially during childhood and adolescence, major pruning of redundant "routes" occurs. This neural pruning prepares the individual for the tasks of adulthood, but in the course of the changes, an "alternative route" may be cut off in a person with schizophrenia unmasking the problematic "main route", and thus the symptoms of schizophrenia.

Information is transmitted through these neural circuits, or "routes", via a relay of chemicals called neurotransmitters. There are probably hundreds of neurotransmitters in the brain. Substantial research is directed at better understanding how neurotransmitter systems work in healthy brains and in brains with schizophrenia, but little is known for sure. One hypothesis that is the focus of a great deal of research is that the dopamine neurotransmitter system in a part of the brain involved in emotion and information processing, the mesolimbic system, is involved in hallucinations and delusions. A related hypothesis is that the dopamine system in another brain area--the prefrontal cortex--is involved in the decrease in experience of emotions and other negative symptoms of schizophrenia. However, there are hypotheses that many neurotransmitter systems may be involved in schizophrenia, including norepinephrine, acetylcholine, and serotonin, to name just a few.

Possible Causes of Schizophrenia

Like pneumonia, which can be caused by various bacteria, viruses, or chemicals, schizophrenia probably has multiple causes, all of which affect the brain in related ways. Research suggests that both genes and environmental factors are involved in developing schizophrenia. While 1 out of every 100 persons has schizophrenia, having a biological relative with schizophrenia increases a person's risk of developing this disorder. A person who has a genetically identical twin with schizophrenia has a 50% chance of having schizophrenia and a 50% chance of not having schizophrenia. A person with a sibling or a parent with schizophrenia has a 10% of having schizophrenia and 90% chance of not having schizophrenia. Thus, research is aimed at finding both the genetic factor that may put a person at increased risk for schizophrenia, and the environmental factors that may be involved. There is active and exciting research to find the genes that increase risk for schizophrenia. Three areas on various chromosomes have been linked to schizophrenia in more than one study; however, the actual gene that increases risk for schizophrenia has not yet been found.

The search for possible environmental factors is in very early stages. One prominent theory is that schizophrenia results from altered brain development during fetal life, occuring from in utero environmental stressors. For example, several, but not all, studies have shown that individuals who were fetuses during influenza epidemics are at increased risk of schizophrenia. A few studies have shown that indiivuduals that were fetuses and their mothers endured severe starvation during that preganancy are at increased risk for schizophrenia. Another study has shown that Rh incompatibility between mother and fetus increases risk for schizophrenia. During fetal life the brain is actively developing. The theory is that these stressors somehow interfere with brain development during a critical stage. In post-mortem studies the brains of individuals with schizophrenia have been examined. Here, several researchers have found that the organization of brain cells was more random than in the brains from mentally healthy individuals. In addition, they have found "nests" of brain cells in patients with schizophrenia in the mesolimbic areas of the brain, suggesting that these cells were somehow stopped in their programmed migration to their final resting place. These and other studies hold promise for our eventual understanding of how genes and environment may interact to cause schizophrenia. Regardless, evidence is overwhelming that schizophrenia is a biologically based illness and that the previous view that parents or families cause schizophrenia is totally without merit.

Treatment of Schizophrenia

Antipsychotic medications are the cornerstone of treatment of schizophrenia. It is clear that antipsychotic medications eliminate or lessen the symptoms of schizophrenia in most patients. Without medications, symptoms will almost always occur. With each reoccurance of symptoms, the symptoms usually take longer to get better, and may not respond as well. When individuals with schizophrenia have repeated exacerbations of symptoms , or "relapses", they may often develop chronic symptoms that do not respond well to medication. The goal of medication treatment is to take medications when symptoms first occur, and to stay on medications even if symptoms go away entirely, to help prevent future relapses. Research now suggests that ongoing hallucinations and delusions are symptoms of a toxic brain process, that may be further damaging the brain. Control of the symptoms may also mean that this brain damaging process is also halted. Regardless, several studies have shown that the earlier a person with schizophrenia gets treatment, the more mild the illness.

Antipsychotic medications may have troublesome side effects. This is especially true for the older medications (chlorpromazine, thioridazine, mesoridazine, fluphenazine, trifluoperazine, perphenazine, thiothixene, molindone, loxapine, haloperidol), where side effects such as a "zombie" feeling, muscle stiffness, sedation, dry mouth, constipation, blurred vision, and many other side effects are very common. Newer medications (risperidone, olanzapine) offer the hope of being an effective treatment of hallucinations and delusions, with many fewer side effects. We are finding that patients are more willing to take the newer medications since the side effects are few, and most patients report no side effects at all on these newer medications. However, the newer medications do not work for everybody and still cause side effects in some people. Like the treatment of diabetes with insulin, the antipsychotic medications control the symptoms but do not cure the disease. Thus, there continues to be active research to find newer and better medication treatments.