Usually, mental illness grabs the public’s attention when it’s linked to a terrible tragedy, such as a mass shooting or a particularly heart-wrenching suicide. The public’s reaction usually is to mourn, and then to go about their lives. They dismiss the mentally ill by thinking, “These people are weak. They were brought up wrong. They’re crazy. They have something wrong with them.”
Now, however, in her new book Infectious Madness: the Surprising Science of How We “Catch” Mental Illness (Little, Brown; October 6, 2015) award-winning investigative science writer Harriet A. Washington presents compelling evidence that mentally ill people weren’t merely “born that way.” She claims that many mental illnesses aren’t genetic. They’re caused by viruses, much the same way viruses cause the common cold, chickenpox, or the flu.
Washington says that she happened on the idea in 1997 while reading a study that linked schizophrenia to a virus that was killing horses and sheep in Central Europe. The report piqued her curiosity and she began a remarkable trek through years of cutting-edge research and fascinating case studies. She wasn’t alone. More and more scientists began to question how many cases of mental illness may be caused by genetics, stress, and psychological factors—and how many might be caused by viruses.
To fully appreciate this phenomenon, we have to understand the place that viruses hold in our world and our bodies. “The earth alone holds five million times more microbes than there are suns in the universe,” Washington writes. “It is home to five nonillion infinitesimal beings—that’s a five followed by 30 zeros.
“Five million bacteria teem in every teaspoon of seawater,” she says, adding that our intestines alone contain more than one hundred trillion viruses, fungi, protozoans, and bacteria. “These single-celled guests outnumber your cells ten to one.” she writes.
“These microbial fellow travelers make up our microbiomes, which constantly adjust in type and numbers on different sites of the body,” she writes. “And our health, including our mental health, changes with them.”
In the book, Washington presents compelling evidence that links the virus that causes strep throat to cases of obsessive-compulsive disorder. She shows that bacteria from our bellies leaking into the blood stream may have been factors in cases of autism. Instances of women getting the flu while pregnant have been linked to development of schizophrenia in children. Many cases of Alzheimer’s, Tourette’s syndrome, bipolar disorder and anorexia can be caused by bacteria, parasites or viruses.
And it isn’t just the people who are suffering from these diseases that feel the effects of mental illness. In her book, Washington shows how infectious mental illnesses can hinder a society culturally, socially and economically. She argues that the issue of mental illness can shape a society in different ways—ways that surround issues at the heart of American society. Why does a culture tolerate violence? How does the culture encourage it? How does a culture foster even more intense violence, such as lynching, or the Holocaust? Could a portion of these actions be caused by a bug in the air?
The good news though, according to Washington, is that there’s hope. Things like genetics, stress and trauma still play their role in the battle against mental illness, but for the 10-15 percent of sufferers whose condition has been caused by infection, there are antibiotics, vaccinations and other strategies that may provide treatment or prevention. In these cases, doctors are provided with a specific medical target to combat: an infection and the damage it’s caused.
By addressing mental illness as just that—an illness—Washington attempts to strip away some of the social stigma that has surrounded these diseases for generations. She also provides hope that cures to these terrible afflictions, like the long sought-after cure to the common cold, may one day be at hand.