Schizophrenia Daily News Blog

New Understanding of How Flu Virus Exposure During Pregnancy May Increase Risk of Schizophrenia in Child

There is a significant amount of research showing an increase risk of schizophrenia for a fetus that is exposed to influenza (the flu virus). This has often been part of the theory for why certain times of the year for a baby's birth shows increased rates of schizophrenia, the critical developmental period coincides with the flu season. Recently, Paul Patterson a neuroscientist from the California Institute of Technology discusses how this flu virus may be causing schizophrenia and where treatment research should be headed.

This is particularly important news because previous research on influenza exposure during pregnancy by Dr. Alan S. Brown, from Columbia University in New York, found that approximately 14% of schizophrenia cases seem to have been caused by influenza during pregnancy. Other research has also shown that children who born to mothers who suffer from flu, viruses and other infections during the pregnancy are at significantly increased risk of schizophrenia - up to 700% higher than children who are not exposed to flu/viruses during the first 13 weeks of pregnancy (see full info on flu exposure during pregnancy).

Women who get respiratory infections such as influenza in the second trimester of pregnancy are up to seven times more likely to have a child with schizophrenia. There is also a higher risk of autism.

Paul Patterson said this risk was much greater than any known genetic influence.

Professor Patterson and his research team used pregnant rats and administered the flu virus during critical periods and then monitored the babies after birth.

"The offspring had strikingly abnormal behavior consistent with things that have been seen in schizophrenia and autism, like disrupted social behavior, fear of novel situations and increased anxiety," Professor Patterson told delegates at the World Congress of Neuroscience yesterday.

The interesting part of the research that may lead to new treatments is that instead of the virus directly affecting the fetus, Patterson's research team discovered that the fetus was affected by the mother's immune response, which seemed to have an adverse effect.

"The proteins produced by the mother's immune system to fight the infection seemed to be linked to the problem," he said.

The specific protein, interleukin 6 is produced when a pregnant woman is fighting the flu virus.

"We found that if you block one protein in particular (interleukin 6), then the offspring seem to be completely normal, and presumably their pathology will be too."

Additional Reading:

Australian radio broadcast on the subject of flu during pregnancy and mental illness. There is a written transcript of part of the broadcast at this link: Flu and Mental Illness / Schizophrenia (Thanks Cannonier)

Flu link to schizophrenia Source: The Age

Flu During Pregnancy May Trigger Schizophrenia, Autism in Child Source: Fox News