How Psychiatrists Navigate the Complexities of Diagnostic Reasoning

 

With mental health problems being more openly discussed in public, and individuals with mental health issues becoming an increasingly important and sometimes critical voice in mental health care, the way psychiatrists practice their craft has also become an object of deeper interest for a broader audience. One central aspect of psychiatric practice is diagnostic reasoning. 

When you visit a psychiatrist because you are suffering, you expect them, among other things, to determine whether you suffer from a mental disorder and, if so, which one. While it's crucial to recognize that this is part of a psychiatrist's job description, what is not trivial is the further question: how exactly does a psychiatrist arrive at the diagnostic conclusions they write in their reports and communicate to their patients? How does the psychiatrist know what the patient’s mental disorder is?

A swift response that someone at least vaguely familiar with psychiatry might give is, “Well, they ask the patients for their symptoms and compare these to the list of mental disorders in the DSM/ICD, which tells them what the diagnosis is,” or something along those lines. Though tempting to close the matter here, it is not that easy. Criteria and symptom lists do not apply themselves to patients; it has to be judged whether they apply to the patient. Furthermore, patients are imperfect sources of information. Imperfect in the sense that they will not automatically and correctly tell you all their symptoms, and sometimes they may claim to have symptoms but misjudge their problems. 

For example, some patients think it is normal to be socially isolated as they have been so for many years, so they will not mention social isolation as one of their problems. On the other hand, patients may say they ruminate about something, while the pattern of cognition that constitutes their “rumination” is more accurately classified as generalized worrying, in the language of psychopathology. These cases show that the process of psychiatric diagnostic reasoning implies more complicated patterns of reasoning and information gathering. A truism for any clinician supporting this is: You can't just pick up a DSM and be good at diagnostics; diagnosing is a skill to learn.

Just picking up the DSM isn't enough; diagnosing is a skill!

If this is so, how does proper psychiatric diagnostic reasoning work? Not many philosophers of psychiatry have attempted to provide a theory of this practical aspect of the epistemology of psychiatry. Some work can be found among scholars committed to the Phenomenological Tradition of psychiatry, some in the works of those focusing on the interpersonal quasi-hermeneutic sense-making processes between clinicians and patients, and finally, some thoughts are to be found among philosophers of psychiatry approaching the field from the perspective of philosophy of science.

In my recent book “How Does The Psychiatrist Know?”, the first book-length treatment of psychiatric diagnostic reasoning, I side with those approaching it from a philosophy of science perspective. I argue we should consider how the procedures of clinical psychiatric diagnostics typically look, i.e., what is taught in many of the central textbooks on psychiatric diagnostics and the standards of the leading psychiatric expert communities. Based on this, psychiatric diagnostic reasoning can largely be seen as a cognitive modelling process, quite similar to the procedures we see in scientific modelling.

For clinicians, philosophers, and anyone else willing to dig through an academic textbook to get an idea of the whole story I put forward, the book is available open access.

 

Adrian Kind is a postdoctoral researcher at the Charité Medical University in Berlin, Germany. He holds a PhD in Philosophy and master degrees in Philosophy as well as Psychology. He is a psychodynamic psychotherapist in advanced training. His main areas of interests are philosophy of psychiatry, philosophy of psychology and philosophy of medicine. He also works on philosophy of sports and philosophy of religion.