The Value of Medical Skepticism in Psychiatry


On Thursday November 2, 2017 the Bates philosophy department sponsored a talk by Kathryn Tabb, an Assistant Professor of Philosophy at Columbia University.

Tabb has recently been studying John Locke’s theories on medical explanation, which she calls “early modern medical skepticism.” Tabb has found that his line of skepticism applies to today’s times.

The equivalent of anatomy, according to Locke, is walking in the woods when one is supposed to make a map of an entire landscape. In getting caught up in the details like the location of certain trees and rocks, it is impossible to get a general sense of the landscape.

“So if you’re thinking about mental illness,” started Tabb, “and if you think it’s not going to do you any good to look at what the blood is doing or what the cells are doing, or what the nerves are doing, what are you going to think about? You’re going to think about experience.”

Indeed, Tabb believes that knowledge should be a means, not an end, in medicine. After researching Locke and his contemporary, Thomas Sydenham, Tabb opined that “there’s what looks like an abyss of causal explanation underlying diseases. We just can’t know much about what causes disease, but… we can still get somewhere with curing diseases if we look at the clinical picture.”

In the proceeding section of the talk, she was mainly concerned about how the Diagnostic and Statistical Manual of Mental Disorders (DSM) has influenced clinical research. The DSM is a manual for clinicians to diagnose patients with mental illnesses. It is also the same tool that researchers use when researching psychiatric phenomena. Tabb sees this as a cause for concern.

“We only think of mental illnesses in the categories we get in the DSM, but a lot of people suffer in terms of their mental health and are below the threshold for a diagnosis that is in the DSM…This is a problem for the clinic, but it is also really a problem for research, because it means researchers are only researching a small percentage of the population,” explained Tabb.

Tabb went further to argue that the DSM has become something like an epistemic prison, since it constrains both the knowledge we can acquire about mental illness and the kind of inquiry we can do. As a result of this, people in multiple medical fields have looked to alternative ways of diagnosing illnesses.

“There are a lot of general categories of disease,” Tabb continued, “and for many of those categories we know how to help people. We know that a combination of drugs and talk therapy is helpful for a large percentage of the human population. A lot of people aren’t getting those services.”

So what to do? Per Tabb, “The NIMH, the National Institution of Mental Health, thinks we should get rid of the clinical categories and just do the basic science. And the hope is that then cures will come out of that, and on the basis of those cures we can draw new diagnostic categories.”

Tabb believed this to be a step in the wrong direction. For her, there is no one thing that we can target when it comes to psychiatry. Mental illnesses usually stem from a plethora of causes including environment and genetics.

According to Tabb, the best approach to using the big data that the NIMH has collected so far is through the process that Locke and Sydenham came up with centuries ago: “You think about the nature of the disorder, you think about what it is you want to cure, what are the needs that people have, and then you use that to think about what sort of questions scientists should think about asking when they use these massive data sets.”

Hopefully, through this approach, we can help expand the realm of possibilities in psychiatry.