Saturday, September 7, 2013

Psychiatry - Science and Pseudoscience

I finished the first chapter in Philosophy of Pseudoscience: Reconsidering the Demarcation Problem by Pigliucci and Boudry.  I became aware of Massimo Pigliucci and his work back in 2002 when I read his book on Intelligent Design and since then have discovered his blog Rationally Speaking where he has recently posted his best papers from his careers as a scientist and a philosopher.  He writes very clearly on the philosophy of science and has such a command of the field that he can include a history lesson of relevant references.  He also does not shy away from controversy or the apparent lack of a clean solution to a problem.  One of the central concepts in his chapter is this chart of empirical knowledge versus theoretical understanding. (click to enlarge)

The purpose of this essay is to look at possible boundaries between science and pseudoscience as well as a couple of interesting observations as they apply to psychiatry.  One of his key concepts is that the lines of demarcation are not necessarily sharp and the variables are not necessarily linear.  He uses the above graph of empirical knowledge versus theoretical understanding as an example.   Starting in the upper right corner of the diagram we have hard sciences with particle physics given as the most clear cut hard science.  I like to think about my undergraduate chemistry experience as being hard science.  Even introductory chemistry exposes the student to an amazing array of facts, observations, and theories that are incredibly accurate.  From there, chemistry majors build on their ability to measure specific compounds, synthesize them and study the theory in Physical Chemistry.   I don't think that there is any doubt that chemistry as a field is not too far removed from particle physics in terms of empirical knowledge or theoretical understanding.  String physics has much theory but is low in terms of empirical support.  He refers to evolutionary psychology,  scientific history and Search for Extraterrestrial Intelligence (SETI) as a "proto-quasi science" cluster with decreased amounts of theory and empirical support.  Other fields like the so-called "soft sciences" of sociology, economics, and psychology have a fair amount of empirical knowledge but less theoretical understanding.  The true pseudosciences are in the zone with astrology, HIV denialism, and Intelligent Design.  From the history of psychiatry - Freudian psychoanalysis and Adlerian psychology would also be included here but there is also a list of theories from general medicine and surgery that would also qualify.

In psychology and psychiatry a central philosophical problem is the so-called hard problem or the explanatory gap between the neurobiology of conscious states and subjective experience.  This is exactly where psychiatry resides.  A lot of political criticism of psychiatry involves the ability to parse these states and accurately classify different conscious states.  Resolving the hard problem would move psychiatry and psychology firmly to the right in the demarcation diagram but probably not nearly as far as particle physics or maybe not even as far as molecular biology.

The relevant question for me of course is where psychiatry fits on the plane of empirical knowledge x theoretical understanding.  What about medicine in general?  Could we plot a plane of medical and surgical sub specialties on this plane instead of the hard and soft sciences?  Does medicine and surgery have theories or practices end up in the same zone as Freudian psychoanalysis.  Of course they do.  A great example from my days as a medicine intern was highlighted by Ghaemi as "The cult of the Swan-Ganz catheter."  In the places where I trained, anyone with moderately serious cardiopulmonary problems was at risk for placement of a Swan-Ganz catheter.  The actual person inserting the catheter could be a medicine resident, a cardiologist, or an anesthesiologist.  Since the intern is responsible for doing the initial history and physical exam, I witnessed the placement of a large number of these catheters.  Once placed they gave an impressive number of parameters on ICU monitors.  We were routinely grilled about the meaning of these parameters by attending physicians on rounds.  It all seemed very scientific.  The cult of the Swan-Ganz catheter was subsequently disproved by randomized clinical trials.  This standard of care from the 1980s and 1990s disappeared much faster than Freud.

The best way to plot medicine and psychiatry on Pigliucci's empirical knowledge versus theoretical understanding plane would be to consider the clinical basic sciences taught in the first two years of medical school.  In my experience that was anatomy, neuroanatomy, histology, microbiology, biochemistry/molecular biology, genetics, pathology, physiology, pharmacology, epidemiology, and statistics.  Practically all clinical specialties carry these basic sciences forward in one form or another.  The research literature in any particular specialty in full of theory and techniques from these basic sciences.  The psychiatric literature cuts across all of the basic sciences in the same way as other specialties.  At the minimum, some of psychiatry will be at the level of molecular biology on the diagram in some areas and at the level of psychology in others.  Hopefully the unscientific theories will be relegated to the lower left hand corner of the diagram as unscientific and not stand the test of time.

I think that Professor Pigliucci's conceptualization is a very useful one.  I expect that he will continue to refine these ideas.  I think that measurement precision and categorization may be important dimensions to add to these concepts.  As Merskey has pointed out both the phone book and the periodic table are much more accurate forms of categorization than any scheme of medical classification.  I think that probably says a lot about the underlying scientific dimensions and how measurement is done.

George Dawson, MD, DFAPA

Ghaemi SN.  A Clinician's Guide to Statistics and Epidemiology in Mental Health.  (2009) Cambridge University Press, Cambridge, UK.  p. 91.


  1. We should start with the fact that psychiatry medicine in general are not sciences at all, but rather professions that would use whatever science they can find and fill in with art, much like engineering (which was my undergraduate field). Engineering, however, enjoys reliance on much more science that we can find to help in the practice of psychiatry.

    I love the diagram above, but I also like Jaspers' distinction between understand (meaningful connections) and explanation (causal connections) which makes it no surprise that:

    "This standard of care from the 1980s and 1990s disappeared much faster than Freud."

    1. Thanks for your observations. I agree with you about engineering and medicine but would say that they are professions that have the use of science as a primary goal. For example, from medical ethics: "A physician shall continue to study, apply,and advance scientific knowledge, make relevant information available to patients, colleagues, and the public, obtain consultation, and use the talents of other health professionals when indicated."

      I am a member of the IEEE, not because I am an electrical engineer but because I worked with a lot of them on EEGs and electrophysiology and needed access to their literature. The practical scientific skills of engineers are amazing and physicians have a lot to learn from that approach.

  2. I don't get the placement of HIV vs. climate science. We actually understand a lot about HIV both theoretically and empirically at this point. However, the theoretical understanding of climate science is actually very primitive as all the predictions are falling apart. There are just too many independent variables.

  3. Oh I see, it was HIV denialism. in that case it should be zero on both axes.

    1. Sorry about that - I agree it might be clearer on the diagram if both words were on the same line.