The Things We Know That Just Ain't So

Last week the American Psychological Association adopted a resolution calling for "full marriage equality for same-sex couples."

This is the same organization that, until 1975, classified homosexuality as a mental disorder (as did the American Psychiatric Association until 1973).

I freely admit that I have never been a fan of diagnostic criteria in mental health. After all, the same mental health professionals who once said homosexuality was a mental disorder now have diagnostic criteria for such "illnesses" as "oppositional-defiant conduct disorder." A child who consistently behaves badly is mentally ill? Seriously? I guess it was too much to hope that organizations that de-medicalized a phenomenon of human behavior in the 1970s would know better than to medicalize other phenomena of human behavior in more recent decades. Perhaps we have this diagnosis so parents will accept the notion that professional counseling is a better option than regular opening of a can of whoop-ass. A randomized clinical trial of that would be interesting.

It is sometimes tempting to join the camp of those who are skeptical of the value of the mental health professions altogether. But there is no question in my mind that people with schizophrenia and major depression have benefited greatly from scientific advances. So I differ with my father, who once remarked (probably mainly to steer me away from it) that psychiatry was a terrible waste of a good medical education.

Some days, though, I wonder, especially when it seems at least half the patients I see during a shift in the emergency department have been diagnosed with bipolar disorder.

But let us not come down too hard on the specialty of psychiatry. Recently a colleague called to my attention a condition called "status lymphaticus," which was the subject of a fascinating article in the journal Medical History. This condition was invented to explain otherwise mysterious cases of sudden death in previously healthy people, especially children. For many decades in the 19th and early 20th centuries, doctors published articles in medical journals on this disease. Sadly, this invention amounted to more than mere foolishness, because it led to the belief that the thymus gland in young children was sometimes too large and should be surgically removed.

The frequent performance of such useless surgery, with the inevitable complications that might accompany any surgery, was bad enough. But after therapeutic use of x-rays came along, the practice became widespread of irradiating the thymus gland in children. This was especially common for those who were going to have surgery and whose thymus looked "large" on chest x-ray. We now know that there is a wide range of normal in the size of this gland in young children, but in those days it was thought a large gland put the child at risk for sudden death when general anesthesia was administered. (In fact, of course, it was the anesthesia itself that was the problem.)

If you are a student of medical history, as I am, you may know that thymic irradiation was accompanied by tragic consequences, as it exposed to x-rays the nearby thyroid gland. The thyroid is quite sensitive to radiation, and the result was an astonishing number of cases of thyroid cancer.

One of my favorite quotations (from which the title of this entry is taken) has been attributed to Mark Twain and Will Rogers, among others: "It ain't what we don't know that gets us in trouble; it's the things we know that just ain't so."

I suspect there are a lot of things in 21st-century medicine we know that will one day prove to be wrong. I would like to think that as medicine has become more scientific, and more and more doctors skeptically demand that knowledge meet the highest standards of what we call evidence-based medicine, the number of "things we know that just ain't so" will steadily decline.

By the way, the journal Medical History is online and free, and I highly recommend it. It helps to remind us of where we have been - and to give us greater insight into how far we still have to go.