Schizophrenia: What is It?

Schizophrenia is a term used to describe a complex, extremely puzzling condition--the most chronic and disabling of the major mental illnesses. Schizophrenia may be one disorder, or it may be many disorders, with different causes. Because of the disorder's complexity, few generalizations hold true for all people who are diagnosed with schizophrenia.

With the sudden onset of severe psychotic symptoms, the individual is said to be experiencing acute schizophrenia. APsychotic@ means out of touch with reality, or unable to separate real from unreal experiences. Some people have only one such psychotic episode; others have many episodes during a lifetime but lead relatively normal lives during the interim periods. The individual with chronic (continuous or recurring) schizophrenia often does not fully recover normal functioning and typically requires long-term treatment, generally including medication, to control the symptoms. Some persons who suffer from chronic schizophrenia may never be able to function without assistance of one sort or another.

Approximately 1 percent of the population develop schizophrenia during their lives. This disorder affects men and women with equal frequency, and the information in this handout is equally applicable to both. The first psychotic symptoms of schizophrenia are often seen in the teens or twenties in men and in the twenties or early thirties in women. Less obvious symptoms, such as social isolation or withdrawal or unusual speech, thinking, or behavior may precede and/or follow the psychotic symptoms.

Sometimes people have psychotic symptoms due to undetected medical disorders. For this reason, a medical history should be taken and a physical examination and laboratory tests should be done during hospitalization to rule out other causes of the schizophrenia.

SCHIZOPHRENIA IS NOT ASPLIT PERSONALITY@

There is a common notion that schizophrenia is the same as Asplit personality@--a Dr. Jekyll-Mr. Hyde switch in character. This is not an accurate description of schizophrenia. In fact, split or multiple personality is an entirely different disorder that is really quite rare.

IS SCHIZOPHRENIA A NEW DISEASE?

Although the term Aschizophrenia@ was not used until the early 20th century, the disorder has existed for a great many years and has been found in all types of societies.

In Western society, Amadness@ or Ainsanity@ was not generally regarded as a health problem until the early 19th century. At that time, a movement to offer more humane treatment to the mentally ill made it possible for them to receive more scientific, medical treatment. The mentally ill were unchained, released from prisons, and given more appropriate care. Several categories of mental disease were subsequently identified. By the early 20th century, schizophrenia had been distinguished from manic-depressive illness, and subcategories had been described. In 1911, Dr. Eugene Bleuler, a Swiss psychiatrist, first used the term, Athe group of schizophrenias.@ Despite disagreement among scientists as to precisely what conditions should or should not be included in this group, the term has been commonly used since then.

WHAT CAUSES SCHIZOPHRENIA?

There is no known single cause of schizophrenia. As discussed later, it appears that genetic factors produce a vulnerability to schizophrenia, with environmental factors contributing to different degrees in different individuals. Just as each individual=s personality is the result of an interplay of cultural, psychological, biological, and genetic factors, a dis-

organization of the personality, as in schizophrenia, may result from an interplay of many factors. Scientists do not agree on a particular formula that is necessary to produce the disorder. No specific gene has yet been found; no biochemical defect has been proven responsible; and no specific stressful event seems sufficient, by itself, to produce schizophrenia.

IS SCHIZOPHRENIA INHERITED?

It has long been known that schizophrenia runs in families. The close relatives of persons suffering from schizophrenia are more likely to develop schizophrenia than those who are not related to someone with schizophrenia. The children of a schizophrenia parent, for example, each have about 10 percent chance of developing schizophrenia. By comparison, the risk of schizophrenia in the general population is about 1 percent.

Over the past 25 years, two types of increasingly sophisticated studies have demonstrated the importance of a genetic factor in the development of schizophrenia. One group of studies examined the occurrence of schizophrenia in identical and fraternal twins; the other group compared adoptive and biological families.

Recent studies of twins have confirmed the basic findings of earlier, scientifically less rigorous studies. Identical twins (who are genetically alike) generally have a higher rate of Aconcordance@ for schizophrenia than fraternal twins (who are no more genetically alike than ordinary siblings). AConcordance@ occurs when both members of a twin pair develop schizophrenia. Although studies of twins provide convincing evidence of an inherited factor in schizophrenia, the fact that concordance for schizophrenia among identical twins is only 40 to 60 percent suggests that some type of environmental factor or factors also must be involved.

A second major group of studies looked at adopted children to examine the effects of heredity and environment. In Denmark, an exhaustive investigation of the mental health of adopted-away children of parents suffering from schizophrenia was conducted. These children were compared with adopted children whose biological parents had no history of mental illness. A comparison was also made of the rates of mental disorder among the biological relatives of two groups of adoptees--one known to be suffering from schizophrenia and the other without a history of mental illness. Findings of adoption studies have indicated that being biologically related to a person suffering from schizophrenia increased the risk for schizophrenia, even when the related individuals have had little or no personal contact.

These studies indicate that schizophrenia has some hereditary basis, but the exact extent of this genetic influence needs further exploration. Most scientists agree that what may be inherited is a vulnerability or predisposition to the disorder--an inherited potential that, given a certain set of factors, can lead to schizophrenia. This predisposition may be due to an enzyme defect or some other biochemical abnormality, a subtle neurological deficit, or some other factor or combination of factors.

We do not yet understand how the genetic predisposition is transmitted and cannot predict accurately whether a given person will or will not develop the disorder. In some people, a genetic factor may be crucial for the development of the disorder; in others, it may be relatively unimportant.

ARE THE PARENTS AT FAULT?

Most schizophrenia researchers now agree that parents do not cause schizophrenia. In past decades, there was a tendency for some mental health workers to blame parents for their children=s disorder. Today, this attitude is generally seen as both inaccurate and counterproductive. Mental health workers now commonly try to enlist family members= aid in the therapeutic program and also show a heightened sensitivity to the very real feelings of burden and isolation many families experience in their attempts to care for a family member suffering from schizophrenia.

IS SCHIZOPHRENIA CAUSED BY A CHEMICAL DEFECT?

Although no neurochemical cause has yet been firmly established for schizophrenia, basic knowledge about brain chemistry and its link to schizophrenia is expanding rapidly. Neurotransmitters--substances that allow communication between nerve cells--have long been thought to be involved in the development of schizophrenia. It is likely that the disorder is associated with some imbalance of the complex, interrelated chemical systems of the brain. Although we have no definite answers, this area of schizophrenia research is very active and exciting.

IS SCHIZOPHRENIA CAUSED BY A PHYSICAL ABNORMALITY IN THE BRAIN?

Interest in this research question has been stimulated by the development of CAT scans (Computerized Axial Tomography) - a kind of x-ray technique for visualizing the structures of living brains. Some studies using this technique suggest that persons suffering from schizophrenia are more likely to have abnormal structure (for example, enlargement of the cavities in the interior of the brain) than are normal persons of the same age. It should be emphasized that some of the abnormalities reported are quite subtle. These abnormalities have not been found to be characteristic of all persons suffering from schizophrenia nor to occur only in individuals with schizophrenia.

A more recent development is the PET (Positron Emission Tomography) scan. In contrast to the CAT scan, which produces images of brain structures, the PET scan is a way of measuring the metabolic activity of specific areas of the brain, including areas deep within the brain. Only very preliminary research has been done with the PET scan in schizophrenia, but this new technique, used in conjunction with other types of scans, promises to provide information about the structure and function of the living brain.

Other special imaging studies that may increase our understanding of schizophrenia include MRI, CBF, and computerized EEG measures. MRI stands for magnetic resonance imaging, a technique involving precise measurements of brain structures based on the effects of a magnetic field on different substances in the brain. This technique has sometime been referred to as nuclear magnetic resonance (NMR) imaging. In rCBF, or regional cerebral blood flow, a radioactive gas is inhaled, and the rate of disappearance of this substance from different areas of the brain gives information about the relative activity of brain regions during various mental activities. The computerized EEG (electroencephalogram ) is a kind of brain wave test that maps electrical responses of the brain as it reacts to different stimuli. All of these imaging techniques are being used for research. They are not new forms of treatment.

Prepared by

SCHIZOPHRENIA RESEARCH BRANCH

U. S. Department of Health and Human Services

For More Information about Mental Illness:

Alliance for the Mentally Ill

NAMI of Greater Chicago

1536 West Chicago Ave.

Chicago, IL 60622

312-563-0445

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