For many people, keeping well doesn’t involve taking good advice. After decades of public health campaigns in favor of low-fat diets, moderate exercise, and stress management, it’s still hard to get Americans to comply. As a society, we are so sold on drugs and surgery as the answer to illness that many of us only register two states of health: Either you are sick or you’re not sick. In the first case, you go to the doctor’s, who is expected to fix you.
The choice should be broader than being sick or not. “I am well” means much more than the absence of active disease. What the public – and most doctors – hasn’t found out is that the cause of illness is becoming more and more murky. It’s not just germs and genes. The germ theory of disease held sway for over a century after the discovery of microbes and the arrival of antibiotics to combat them. Gene therapy, long promised as the answer to almost any disease, hasn’t actually achieved much success, although in certain cases, such as cancers that are caused by a simple genetic mutation, targeted drug therapies have been successful.
The bigger picture is that genetics has led us into much more complicated view of the disease process, so complicated that it is beyond the skill of doctors. Too many factors are at work when illness arises, and the disease model itself sometimes breaks down.
A startling article in The Wilson Quarterly covered the current explanations for schizophrenia, which has moved from being a psychiatric disorder to a disorder of the brain. And yet, to quote the article, “It is now clear that the simple biomedical approach to serious psychiatric illnesses has failed in turn. At least, the bold dream that these maladies would be understood as brain disorders with clearly identifiable genetic causes … has faded into the mist.” All simple approaches, from talking to a psychiatrist to taking a pill or holding out for a genetic silver bullet, don’t match reality.
To quote once more, “. . . schizophrenia now appears to be a complex outcome of many unrelated causes—the genes you inherit, but also whether your mother fell ill during her pregnancy, whether you got beaten up as a child or were stressed as an adolescent, even how much sun your skin has seen. It’s not just about the brain. It’s not just about genes.” The fact is that many diseases are turning out to have multiple causes that change from person to person. Depression, which is much more widespread than schizophrenia, is now known to involve many brain centers, to the extent that no two people are exactly alike in their depression.
Therefore, the conclusion that applies to schizophrenia may be announcing a massive trend. “. . . schizophrenia looks more and more like diabetes. A messy array of risk factors predisposes someone to develop diabetes: smoking, being overweight, collecting fat around the middle rather than on the hips, high blood pressure, and yes, family history. These risk factors are not intrinsically linked. Some of them have something to do with genes, but most do not.”
What are we left with when clear, defined causes don’t work?, a term even more vague than risk factors: susceptibility. Susceptibility covers so many things that quite literally everything in life becomes a contributing factor. A doctor can’t make you well because susceptibility goes back all the way to birth. A wide range of mental disorders, including schizophrenia, depression, autism, and Alzheimer’s, are now traceable to slight changes in the brain that appear many years or even decades before the first symptoms arise.
Much of this evidence has been gained through brain scans and genetic typing, yet these indicators aren’t causes. We now know that gene output is highly flexible and always changing, while the brain alters its “soft wiring” constantly. Both are highly influenced by behavior, beliefs, lifestyle choices, diet, and so on. Despite all the new information gained through new technologies, treatment hasn’t generally kept up, and sometimes, as in early signs of a predisposition for cancer, autism, and Alzheimer’s, finding a suitable drug therapy, should one even exist, is years or decades away.
In the next post we’ll discuss what this tremendous shift in explaining illness means for you today, trying to find ways to reduce your susceptibility.
(To be cont.)