Schizophrenia Associated with a Variety of Autoimmune Disorders

By: Laurie Edwards for Body1

According to a new study, the link between disorders of the body and of the mind may be even stronger than previously thought. Autoimmune disorders – anything from rheumatoid arthritis to skin problems – have come under increasing scrutiny in an age of growing chronic illness, and now they are thought to be associated with a higher risk of developing schizophrenia, a rare and potentially devastating brain disorder.

Using Danish patient registries, Dr. William W. Eaton of John Hopkins University and his colleagues analyzed 7,704 patients diagnosed with schizophrenia between 1981 and 1998.

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Understanding the mind/body link: Schizophrenia is a debilitating brain disorder that can be difficult to treat. It affects about 1 percent of the population worldwide. Autoimmune disorders are a large group of conditions that refer to a breakdown in the immune process that classifies tissue as “self” and “non-self”. When this happens, the body begins to attacks its own tissues and can destroy them. Experts found a link between a personal and family history of autoimmune diseases and schizophrenia. Having autoimmune disorders doesn’t directly cause someone to develop schizophrenia; it only increases the likelihood.

According to the study authors, schizophrenic patients and their families “tended to have either high or lower than expected prevalence of autoimmune disorders, especially rheumatoid arthritis, celiac disease, autoimmune thyroid disease and Type 1 diabetes,” so the goal of their work to was to examine the association with these conditions as well as a wide range of autoimmune disorders.

Their results, published in a recent issue of The American Journal of Psychiatry, found that subjects with a history of one or more autoimmune disorders had a 45 percent higher risk of developing schizophrenia.

Despite its appearance in popular television and film, schizophrenia isn’t nearly as common as it is well known. The chronic, severe and debilitating disorder affects about 1 percent of the population around the world. Often, patients hear voices no one else hears and suffer from paranoid feelings that others are plotting against them.

In schizophrenic men, symptoms like hallucinations, delusions, flat affect, social withdrawal and cognitive deficits usually begin to develop in their late teens or early twenties; in women, this process begins in their twenties and thirties.

As a result of this fear, many schizophrenics become withdrawn and have trouble maintaining relationships. Continued use of antipsychotic medications is often an effective way of restoring function and quality of life, but due to side effects or disorganized thinking, may patients have a hard time staying on the drugs.

Experts have yet to pinpoint the cause of schizophrenia, but it appears to be at least partly a combination of genetic vulnerability and environmental factors during a patient’s development. Research suggests there are specific genes that may increase the risk, but as is the case with many other illnesses, the genes do not cause the illness; they merely elevate the chances of developing it.

Autoimmune disorders represent a much larger group of conditions characterized by an inappropriate, exaggerated or inadequate immune response to the body’s own tissues. In a process that is similar to an allergic response – when the immune system reacts to a foreign agent that would normally be harmless to the body – autoimmune disorders occur when the body reacts to its very self.

Since the body can usually distinguish between “self” and “non-self” tissue, disorders like rheumatoid arthritis and Type 1 diabetes represent a breakdown in the control process that makes such distinctions.

Like schizophrenia, the exact cause of autoimmune disorders is still being researched, but many experts believe that viruses or certain drugs may “trigger” this inappropriate response.

Just as it has its part in developing both types of illnesses, family history proved important in this latest study. Schizophrenic patients and their parents experienced a higher prevalence of nine autoimmune disorders when compared to the control group of subjects and parents. Autoimmune disorders linked with schizophrenia include: thyrotoxicosis, celiac disease, acquired hemolytic anemia, interstitial cystitis and Sjogren’s syndrome.

“In future clinical studies, it may be interesting to search for a family history of autoimmune diseases… Eventually, individual or family disease comorbidity may help to elucidate shared etiologic pathways,” said Dr. Eaton.

Last updated: 29-Aug-06