Why Psychiatry Is Still in the Nineteenth Century
Other branches of medicine have made amazing advances. Why not psychiatry?
Posted June 23, 2019
Mrs. A has not been herself for months. Her life is a dull grey. She no longer takes an interest in anything, including her family. Nothing gives her pleasure. She thinks about whether her life is worth continuing. Finally, after much persuasion—because she doesn’t like to think of herself as suffering from a mental disorder—she consults a psychiatrist. What can she expect?
Her psychiatrist is experienced and empathetic. Mrs. A is rather pleased that she is seeing a female; somehow this makes it easier for her to talk about herself. Which is what she does. Her psychiatrist asks very many questions about her current mental state, about her upbringing, about her marriage, about the relationship she has with her children, whether she has many friends, and so on. She makes careful notes.
At the end of the consultation, the psychiatrist tells Mrs. A that she is suffering from depression, that she needs treatment, and that she is likely to recover within about nine months or so, perhaps sooner. Mrs. A, who is a trained scientist, can’t help noticing that her doctor takes no blood samples, does not suggest an X-ray or scan; in fact, the whole diagnostic process is based entirely on the conversation she has just had. Mrs. A goes off with her prescription for some tablets, which her doctor tells her will act mostly on the levels of serotonin in her brain. She also mentions the possibility of psychotherapy.
Down the hall, Mr. B is seeing a cardiologist. He has been having pains in his chest, particularly when he walks upstairs, and playing tennis, which he loves, has become impossible. He has also noticed that he becomes short of breath rather easily. His doctor takes a careful history and tells him that it seems likely that he has a constricted or blocked blood vessel in his heart. But then he refers him for an ECG, a cardiac angiography, to detect exactly where this blockage might be, takes blood to measure certain enzymes, and mentions several other investigations that might be necessary. He also prescribes Mr. B some tablets, telling him that these will relax the blood vessels in his heart and reduce his blood pressure (which was higher than it should be).
At the end of all this, Mr. B will have a precise diagnosis based on a great amount of additional data, whereas Mrs. A will not. Her diagnosis will be based solely on the answers to the questions her doctor asked her. Mr. B will have targeted treatment, directed selectively towards the disorder that is ruining his life. The cardiologist can explain this in precise detail.
Mrs. A asks her psychiatrist whether, and how, altered serotonin can cause depression. Her doctor tells her that the role of serotonin in depression is still unclear. She adds that because drugs acting on serotonin do improve recovery from depression, this is not evidence that low serotonin was the cause, any more than because a band-aid aids a cut’s healing, the cut is not due to the absence of a band-aid. In fact, she adds, many in the field no longer believe in the "low serotonin causes depression" theory. No one really knows why serotonin-acting drugs (among others) are helpful in depression.
If we were to resurrect a cardiologist from the 19th century and seat him at Mr. B’s consultation, he (it would be a "he") would be completely amazed at what had happened to his specialty. Moreover, he would have no idea about what he was seeing: The tests and the examination would be outside anything he knew. The diagnosis would have no meaning for him. The treatments would be unintelligible.
Next door, with Mrs. A, we have a resurrected psychiatrist (though he would have been called an "alienist"). He is not at all confused by what is going on, though some of the questions might be different from the ones he would have asked. The diagnosis would be entirely familiar (though he might call it "melancholia"), but the concept of "serotonin" and the drugs that act on it would be strange. His 21st-century colleague is honest enough to tell him that many patients don’t respond very well to these drugs and that truly new ones have not appeared for many years. Both of them know that a considerate and supportive environment helps recovery, but that the risk of suicide is a real one.
Why this immense gap between what cardiologists and psychiatrists know? They are equally intelligent. They work as hard. They care as much. The answer is both simple and complex. It’s simple in that the reason is the difference in basic scientific knowledge about the heart and the brain. It’s complex in that the reason for this difference lies in the nature of the two organs.
The heart is not a mystery. We know a great deal (not everything) about how it pumps blood around the body. How the muscles contract, and how they are synchronized to act together but in sequence. How the valves control the flow of blood through the heart. We also know how to repair those valves, clear the blockage from blood vessels or replace them, or even the heart itself. Knowledge of the biochemistry of the heart has allowed specific drugs to be developed, targeting defects that may occur as parts of this mechanism. And we also know quite a lot about what predisposes some people to develop heart disease, and so how to prevent it (e.g., not smoking).
None of this applies to the brain, which is a thousand or more times as complicated as the heart. Depression is a disorder of mood and emotion. Though we have some ideas about which parts of the brain are particularly concerned with these functions (e.g., the amygdala), no one knows how the brain produces, say, happiness, and how this differs from, say, sadness—that is, how different patterns in the amygdala code for different emotions. So no one can say what happens when this system malfunctions and results in the abnormally persistent mood we call depression.
If you don’t know how something works, you can’t put it right when it goes wrong. Ask any motor mechanic. We know that adverse events early in life make subsequent depression more likely, but not why. We know how the muscle cells of the heart combine to make it work. We don’t know how assemblies of neurons (nerve cells) combine to generate mood, or thought, or memory, or, indeed, any of the complex psychological events we know the brain can do, even though we know a good deal about the properties of the neurons themselves. This knowledge is important, but it hasn’t, as yet, given us the information we need to understand and therefore treat depression. Or, indeed, any other mental disorder (schizophrenia, bipolar disorder, autism, anorexia, etc.).
Neuroscience, as I tell my students, is as much about what we don’t know (but need to) as about what we do know. We understand the brain as a collection of cells, but not as an organ. We can be reasonably sure that one day, after much effort, much failure, many blind alleys, we will get enough insight into how the brain works so that psychiatrists, as well as cardiologists, really know what they are doing. I won’t be around then, and, I’m sorry to say, neither will you.