.bmp)
.bmp)
Viruses or bacteria may be at the root of schizophrenia and other disordersKey Concepts
Bugs and the Brain
*Mental illnesses once thought to be the result of neurological or psychological defects may be caused by viral or microbial infections.
*The strongest evidence links schizophrenia to prenatal influenza infection; pregnant women who become ill with the flu are more likely to give birth to children who will develop schizophrenia.
*The body’s immune reaction, rather than the infections themselves, may be to blame for the resulting brain damage and psychiatric symptoms.
*Understanding the relation between infections and psychiatric disorders may someday allow us to prevent mental illness using drugs or vaccines.
Schizophrenia is a devastating illness. One percent of the world’s population suffers from its symptoms of hallucinations, psychosis and impaired cognitive ability. The disease destroys relationships and renders many of its sufferers unable to hold down a job. What could cause such frightening damage to the brain? According to a growing body of research, the culprit is surprising: the flu.If you are skeptical, you are not alone. Being condemned to a lifetime of harsh antipsychotic drugs seems a far cry from a runny nose and fever. And yet studies have repeatedly linked schizophrenia to prenatal infections with influenza virus and other microbes, showing that the children of mothers who suffer these infections during pregnancy are more likely to be diagnosed with schizophrenia later in life. In 2006 scientists at Columbia University asserted that up to one fifth of all schizophrenia cases are caused by prenatal infections.Doctors have known for many years that microbes such as syphilis and Streptococcus can, if left untreated, lead to serious psychiatric problems. Now a growing number of scientists are proposing that microbes are to blame for several mental illnesses once thought to have neurological or psychological defects at their roots. The strongest evidence pertains to schizophrenia, but autism, bipolar disorder and obsessive-compulsive disorder have also been linked to bacterial, viral or parasitic infections in utero, in childhood or in maturity. Some of these infections can directly affect the brain, whereas others might trigger immune reactions that interfere with brain development or perhaps even attack our own brain cells in an autoimmune mistake.As scientists tease out the link between infections and psychiatric disorders, they anticipate opening the door to a new world of preventive measures. In the most immediate cases, a simple vaccine or regimen of antimicrobial drugs could rid the body of an infection before it damages the brain. And if our immune system is responsible, we might be able to develop drugs that stifle the effect of the immune response in the brain. The bottom line is, the more we know about the complex roots of mental illness, the better we can fight it.
What Causes Mental Illness?
In 1896 Scientific American published an editorial entitled “Is Insanity Due to a Microbe?” The question seemed logical, given that microbes were starting to be implicated in other diseases. In the editorial, two doctors described how they had injected cerebrospinal fluid of mentally ill patients into rabbits, which later got sick. The doctors concluded that “certain forms of insanity” could be caused by infectious agents, “similar to typhoid, diphtheria and others.”But when Freudian psychoanalysis became popular in the 1930s,the idea was more or less put to rest. Then, in the 1950s, the discovery of DNA as hereditary material sparked a rising interest in genetics as a cause of illness, including mental disorders. Several papers reported a clear hereditary component to diseases such as schizophrenia, but genes were obviously not the whole story—as a number of studies have found, the identical twin of someone with schizophrenia has only about a one-in-two chance of developing schizophrenia himself.Certain environmental influences therefore probably interact with genes to trigger mental illness in a person with a genetic predisposition. Scientists began investigating everything from diet and lifestyle to parental nurturing and geographical location. In 1973 E. Fuller Torrey, now a research psychiatrist at the Stanley Medical Research Institute in Chevy Chase, Md., published an article in the British journal Lancet that revived an idea that had been set aside for decades—could microbial infection cause mental illness?For the next 20 years, a few rogue scientists dominated the field, searching for connections between infections and psychiatric disorders—and the closer they looked, the more they found.
By Melinda Wenner
To read more go to:
As in the days of Noah....
