Is mental illness contagious?
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Philosophers and literary scholars can choose to interpret facts within “the most convincing perspectives, assumptions and causal frameworks,” as Harriet A. Washington explains in the opening chapter of her latest book, Infectious Madness: The Surprising Science of How We Catch Mental Illness. Hard scientists, she says, don’t have the same luxury. They’re bound by a “shared overarching theory,” a worldview that the physicist Thomas Kuhn called Weltanschauung, meaning “what members of a scientific community, and they alone, share.” Biologists couldn’t embrace evolutionary theory, for example, without abandoning creationism.

In medical science, we work within the confines of germ theory, the idea that microorganisms cause infectious disease. Scientists only began to accept germ theory in the 18th century. Before then, they blamed infections on sin and demonic influence, to name just two abstract, occult causes. But Washington, a science writer and former public health fellow, says it’s time to expand this theory to include mental illness.

It’s well-proven, she states, that infection sometimes lies at the root of psychiatric disorders, including schizophrenia, anorexia and OCD. But, as she argues in her exquisitely written and well-supported book, accepting the notion of “catching” mental illness requires blurring the line between afflictions of the mind and body, a false dichotomy exacerbated by a healthcare system grounded in separating mental and physical disease. “When a man lacks mental balance in pneumonia he is said to be delirious,” physician Martin H. Fischer famously said. “When he lacks mental balance without it, he’s pronounced insane.”

Van Winkle’s caught up with Washington to discuss Infectious Madness and rethinking our stance on mental illness.

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Can you explain the general argument you make in the book with regard to the relationship between mental illness and infectious disease?

I used history to illustrate how we tend to take this very binary approach to illness and insist it either be mental or physical, despite abundant evidence that many illnesses are both. I’m simply lobbying to include mental illness in the spectrum of illnesses that are both. The argument is there in history. Now, it’s an issue of readdressing the facts with a more sophisticated understanding of medicine, in particular the relationship between germ theory and medicine that clarifies the fact that we’ve done this for a long time and need to abandon it.

Speaking of germ theory, you explain medical history in terms of paradigm shifts, and argue that we’ve already begun a shift towards recognizing infection as an important cause of mental illness, even if most people don’t realize it. How does this thinking fit into the current germ theory paradigm?

All I’m saying is that, in many cases, mental illnesses are subject to germ theory. Germ theory doesn’t change at all. It’s just a little more inclusive. The traditional causes of mental illnesses do still apply. The researchers who’ve devoted a lot of time and energy looking into this estimate that 10 to 20 percent of mental illness will turn out to be caused by microbes. What I’m claiming is that we have to include infection alongside stress, trauma, genetics. It’s not so much a total renovation of ideas in the way germ theory was, when we were replacing outmoded theories.

Going beyond theory, what does the idea of “catching” mental illness mean in everyday life? How should the average person understand the theory in terms of personal health and hygiene?

It’s a scary concept in some ways, but it’s also a hopeful concept. When you think that one out of every 100 people in this country suffers from schizophrenia — half of them don’t get good treatment — the average person should look at it as something we can actually do something about.

If it turns out, as I think it will, that some cases of schizophrenia are caused by infection, or by everyday influenza, that means that 10 to 15 percent of cases of schizophrenia can be prevented rather simply. The same things our mom told us growing up, that’s what we ought to do. Avoid pathogens. Wash your hands carefully. Cook your food carefully. Make sure surfaces are clean. Get plenty of sleep.

These things are very simple public health actions, which everyone should do for other reasons as well, but now we have the added incentive that they can also prevent against some cases of mental illness, and I think that’s good news.


Would the “infectious madness” model, in fact, lessen stigma?

Initially, many people had hoped that, as we began to find more evidence for physical triggers of mental illness, it would relieve the stigma. Unfortunately, other types of stigma replaced it. People, as I note in the book, sometimes feel that if there’s actually a physiological substrate to schizophrenia, that means it’s something you have that can never be fixed, and start to think, “I need to avoid you, I don’t want to catch this.” So, unfortunately, we’re very adept at creating stigma, despite the facts. I think that a lot of it will have to rely on education.

We’re doing this out of fear and ignorance, I know that one of the things that’s always disturbed me is the misconception that schizophrenics have multiple personalities. That’s just not true. Or that they tend to be violent, which is not true. Treating them as if they are violent unfairly cuts them off from life. So it is important to combat these stigmas whenever we can.

“Some cases of schizophrenia are caused by infection, or by everyday influenza, which means that 10 to 15 percent of cases can be prevented.”

A number of chronic illnesses, such as fibromyalgia, and especially Morgellons, have surfaced in conversation a lot in the past few years, particularly through the growth of online patient communities. Some people believe that Morgellons has infectious roots. What’s your reaction to this dialogue?

My reaction is that we don’t know enough yet. We need research. We don’t know if it’s a real syndrome yet or not; we don’t know if it is indeed caused by microbes.

I noticed something about parents, who were convinced that their children had developed one of a group of diseases, like Tourette's or obsessive compulsive disorder, as a result of a streptococcal infection. When they were tested and it was found their children did not have it, some became very unhappy.

And I thought, “Why are they so upset?” Usually, people are happy not to get a diagnosis, and then I realized, once your child is involved, it’s very difficult not to have a face for the illness, and that was the situation these parents found themselves up against. They thought they had found the culprit. Then they learned that they didn’t and it threw them back into that amorphous situation where their child is sick but they can’t put a face on it.

Insomnia fuses the physical and the mental in an interesting way. We treat the disorder both with cognitive therapy and drugs, and recognize both behavioral and physiological causes for its onset. I was wondering how you’d characterize it in the framework you’ve used to look at other disorders that bridge the mental-physical divide, particularly with respect to infection.

At the University of Texas sleep center, one doctor did these studies where people who are sleep-deprived have lower levels of T-cells and higher levels of inflammatory cytokines. He theorizes that this makes people more likely to develop the flu, one of the prime infections tied to schizophrenia over decades of studies. So, someone not getting enough sleep could eventually — this is all, of course, very speculative — increase their child’s chance of getting the flu. If they got it while pregnant or when their child is young, and the child catches it, there’s a chance that the influenza infection could increase that child’s risk of schizophrenia.

Also, one way our immune system deals with microbial invasions is with a fever, because microbes can only function within a narrow range of temperatures. So, our bodies turn up the heat with a fever in attempts to evict the pathogens. And, actually, fevers tend to rise at night, because you can get a better fever response when you’re sleeping. But people with insomnia can’t get that higher fever going, so they lose one of the tools in fighting microbes, including the microbes that could be implicated in mental illness.

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While reading the book, I noticed that, in many cases where infection actually did cause a mental disorder, the initial explanation implicated some kind of trauma. If we accept that infection belongs in the mental disorder conversation in a more robust way, are we going to question the significance of trauma?

People are uncomfortable with the idea because they think it displaces the prominence of traditional causes. It’s really important to abandon a binary drive. We sometimes have a binary drive where we’re more comfortable when things are either/or. It’s not an either/or case. It’s both. I’m sure there are some disorders more driven by psychosocial factors, like trauma.

But, as people become more adept at being inclusive in looking at disease, they’ll understand it better. For example, think about rabies. No one suggests someone with rabies has it because they weren’t breastfed long enough. We understand it was the bite of an infected animal, and we need to expand that understanding to other diseases when those causal connections are drawn.

“Illness is not an either/or case.”

Was there one medical anecdote or study you came across, and included in your book, that you found most surprising?

What I didn’t know about sleeping sickness. All I know about is what I’ve seen in the movies, or what I’ve read in medical papers. I thought of it as a disease of irrepressible daytime drowsiness, and that’s actually a bit misleading. Compulsion of sleep is only one feature of it — the one that’s captured our imagination — but a Doctors Without Borders doctor wrote that many of her patients become violent and psychotic, and have attacked doctors and each other.

It gripped me so much because it really highlighted what [Johns Hopkins’] Dr. Robert Yolken has said: We don’t know a lot about these organisms or how they affect the brain. Not that I had first-hand knowledge of sleeping sickness, but here I was thinking I know what it is, and then I read the DWB report and realized I had no idea about the scope of this illness, and that it’s largely a mental illness.

This story by  first appeared at Van Winkle's