Get pregnant and get the flu – then cause schizophrenia?

It sounds far-fetched, especially when the mainstream media too often talks oversimplistically of “chemical imbalances” with depression and leaves hanging the idea that genes cause something similar to create schizophrenia.

Nonetheless, more and more evidence is coming out that a pregnant mother-to-be catching the flu can indeed increase that child’s chances of schizophrenia.

And, revising an idea that went out the door after the discovery of DNA and its double helix, scientists are investigating whether other mental conditions don’t have infectious roots as well:

• 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.

The story notes the connection is most compelling with schizophrenia, noting a 5-8 percent greater rate among children born in winter or spring. First trimester exposure to influenza caused the greatest increase in risk.

Studies of lab animals shows that infected mothers tend to have children with higher fear and anxiety levels, among other problems.

In some cases, it may not be the infection itself, but the response of the mother’s immune system that does something to the placental barrier.