Mind & Body

A Modern Study Supports a 100-Year-Old Hypothesis About Schizophrenia

A century ago, medicine just wasn't what it is today. Around the turn of the 20th century, doctors seemed willing to prescribe any variety of questionable remedies, from leeches to heroin to medicinal Coca-Cola. In other words, we're not exactly looking back on that era for guidance — but maybe we should. A new study lines up with a very old theory about the causes of schizophrenia, and it could change the way we look at the disorder.

Related Video: My Schizophrenia Doesn't Make Me A Monster

(Not) All in Your Head

Meet Emil Kraepelin. His might not be a household name like Freud's, but in the late 19th and early 20th centuries he was one of the world's premier psychologists specializing in the disorder dementia praecox — or as it's known today, schizophrenia. Actually, from 1896 up until his death in 1926, he held to a belief that seemed impossible to the next generation of psychiatrists. The disorder, Kraepelin believed, was what he called a "whole-body madness." In other words, schizophrenia isn't confined to the brain; it also has a strong physical component.

Now, the association between schizophrenia and poor physical health isn't controversial. It's long been observed that people with schizophrenia live about 10 to 20 years less than people without it, and the disorder is associated with an increased risk of other health problems including heart disease, diabetes, and suicide. Most modern doctors have assumed that this association went in one direction — schizophrenic people often face homelessness and other factors that put their health at risk, so poor physical symptoms were assumed to have been a secondary feature of the disorder that may or may not show itself based on context.

But according to a May 2018 study led by Dr. Tom Pillinger from King's College London, Kraepelin might not have been so far off after all. If the poor health of schizophrenic people is a result of social factors such as shelter, employment, and access to basic needs, then it should be less pronounced in people who have only recently begun showing signs of the disorder. As it turns out, though, even young people diagnosed with schizophrenia had more markers of inflammation, higher levels of certain hormones, and more heart disease risk factors than those without.

A Body and Mind Problem

Writing for The Conversation, Pillinger described how his team didn't just discover if there was a statistical difference between the health of people with schizophrenia and people without. They also were able to gauge exactly how big that effect was by using a statistical tool known as effect size. You calculate it by subtracting the average value of the control group from the average value of the experimental group, then dividing the difference by the standard deviation, which is a measure of how much the values in each group vary. Essentially, it tells you not only how far apart the averages are from each other, but also how much overlap there is between the two groups. When they found that the effect size of the brain differences was the same as the effect size of the physiological differences, the researchers realized that in all likelihood schizophrenia has a physical component as a primary signifier.

If that's true, then there are a few ways that that relationship could pan out. One explanation could be that effects in the brain ripple out to cause effects in the body, like when the brain produces the stress hormone cortisol, which can cause weight gain, raised blood pressure, and diabetes. Another is that the disorder is rooted in the body instead and that these kinds of issues are reflected in the brain. That's also a phenomenon we've observed before, as when certain rare cancers cause psychosis until the tumor is removed. There's also the possibility that it's not really a question of the chicken and the egg as much as two symptoms that might be tied to a third, as-yet-unknown factor. We don't have all the answers yet, but a more all-encompassing understanding of the disorder can only help people who are suffering from it in the future.

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For more, check out "The Disordered Mind: What Unusual Brains Tell Us About Ourselves" by Eric R. Kandel. We handpick reading recommendations we think you may like. If you choose to make a purchase, Curiosity will get a share of the sale.

Written by Reuben Westmaas June 1, 2018

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