Do Genes Make People Crazy?

The invention of the telescope in the early 1600s led to discoveries that soon disrupted and crashed centuries of belief about the earth, the sun, and the planets.  Something similar is happening in genetics, and in particular the genetics of psychological and psychiatric disorders. The new telescope is genome sequencing. For the first time, genome sequencing technology lets researchers look at the actual genetic makeup, the DNA, of an individual. The technology has become so inexpensive in the past decade that scientists can now read and compare the DNA of many thousands of individuals.

For well over a hundred and fifty years, scientists and the lay public have held as a core belief that the cause of major behavioral disorders, such as alcoholism, schizophrenia, and much else, lay in the affected individual’s genes. When genome sequencing became available early in this century, government and private labs set out with high hopes that “the alcoholism gene” and “the schizophrenia gene” and “the [whatever] gene” would soon be discovered. Once “the gene” was isolated, pharmacology would design a drug to target it and, presto, the disorder would be cured.

It hasn’t turned out that way. What the studies have found, instead, is that an individual’s genetic makeup has next to nothing to do with it.  In my recent book, Empowering Your Sober Self, I outlined how genomics research has wrecked traditional beliefs in “the alcoholism gene.”  Comparing the DNA of tens of thousands of diagnosed alcoholics with tens of thousands of normal people has turned up no significant genetic differences.

A similar disruption is roiling the neighbor fields of psychiatric studies, notably in schizophrenia. A report in the current (May 2017) issue of Scientific American covers the story. Some media headlines had trumpeted discovery of “the schizophrenia gene,” but careful reading of the actual research results showed nothing there.  Schizophrenia turns out to be extremely “polygenetic,” meaning that the DNA of people with that diagnosis shows a wide variety and large number of different genes, all of which are also present in great variety and large numbers in people without. None of the genetic variations rises to statistical significance.

The SciAm review, by Michael Balter, almost reads like a rewrite of my chapter on genetics from Empowering Your Sober Self with “schizophrenia” put in place of “alcoholism.”  It’s a human interest story, in its way, not only about the sufferers from these disorders, and their families and caregivers, but about the scientists in the field. Ironically, the new telescope is mostly in the hands of tradition-steeped researchers deeply invested in the belief that your genes make you crazy, drunk, criminal, stupid, whatever. Some of these scientists are shaken up by the negative messages their new toy is sending.  There’s fifty shades of denial. But, bottom line, the “schizophrenia gene” theory is a bust.

Meanwhile, pay dirt is showing up in research on environmental factors.  People who have psychotic symptoms are three times more likely to have suffered childhood adversity, such as emotional or physical trauma, migration, urban stress, and early cannabis use. Not everyone diagnosed with schizophrenia has a history of childhood trauma, and not all victims of childhood trauma become schizophrenic, but the correlation is strong enough — and much stronger than anything revealed by genome studies — to warrant attention to giving children better childhoods.

And there’s the rub. The theory that your genes make you crazy leads to a neatly packaged result pleasing to the pharmaceutical industry. There’s big money in that approach, even if it only helps with symptoms and is not a cure. By contrast, the insight that bad things in your environment are to blame suggests that the fix lies in ending wars, minimizing income inequality, providing health care for everyone, having universal preschool, ending  traumatic injustices, and stuff like that.  There’s no money in it.

Scientific American has done a good job here in bringing the ongoing disruption in psychiatric theory to a wider audience.

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