Something's Missing: What Psychotherapy Research Leaves Out

It is common to hear, in discussions about the value of psychotherapy research, that nomothetic outcomes leave out some indiscernible inter-personal human "magic". That there is something missing from psychotherapy research, which renders its findings essentially moot. So often do I hear this point in discussions, that I want to take it on and suggest that it presents less of a problem than is generally supposed.

When the "something missing" argument is wielded in a debate about research, two consequences usually seem to be implied:

1. That psychotherapy research cannot tell you very much about what psychotherapy is really like, and so should not be trusted in appraising whether it is helpful.

2. That psychotherapy research does a sort of crass violence to the psychotherapy relationship itself, and that psychotherapy researchers are naive to think they can capture something so delicate.

The "something's missing" argument is often stated as though it were a knock-out blow to the value of outcomes research. It isn't. That something should be left out whenever we attempt to measure or represent something else is a banal truism. It simply presents no problem to the project of learning about reality. I am sure I have quoted Paul Meehl on this question before. In his book on statistical prediction, he refutes those who claim that any aspect of human behaviour is too complex to be in principle predictable from regression models, because humans are "more than" the models in question:

"A cannon ball falling through the air is “more than” the equation S=½g, but this has not prevented the development of a rather satisfactory science of mechanics".

The same goes for all of science (the full reality of a Large Hadron collider is more than the sum of the research produced by the physicists who work with it, but the research they produce does not lack veracity or utility in virtue of that fact) and the humanities too (no quantity of historical books on the American Civil War will ever completely reconstruct the experience of someone who fought in it). In fact, it is inherent to representing a state of affairs in any form other than the original.

So yes, psychotherapy research has "something missing", but that is trivial and we have to either accept the limitation or offer solutions to it (which is to say, become methodologists rather than critics). The choice we have is not between trite, uninformative quantitative research and rich-full-blooded qualitative information, it is between some combination of those two approaches and sheer guesswork. 

Quantitative research does not just forget the magic of the interpersonal encounter, it factors it out in a bid to discover a separate numerical truth: how many people show some sort of measurable improvement (and how much of one)? This can look clumsy, but it is actually necessarily revealing to escape the persuasion of interpersonal charm and the therapeutic relationship. Think of a doctor like John Bodkins Adams, who appears to have been very successful interpersonally. He was sufficiently charming that he received money from many of his patients in their wills and became a extremely successful GP. Only something as crass as a body-count (Bodkin-Adams may have killed as many as 160 of his patients) revealed that something untoward was going on. 

We should think of psychotherapy outcome research as analogous to the body count. Without it, we are too apt to be misled by the charisma and good intentions of the therapy industry. 

Unpacking the "illnessy intuition"

Last summer I wrote a post examining why, in the face of fairly wide dissatisfaction, the concept of schizophrenia seems to show such tenacity. As part of that argument I invoked the idea of an intuition that people have about schizophrenia; namely that it seems there is often something "illnessy" there:

"There is a way in which the diagnosis is very convincing; on the face of it many people who meet criteria for schizophrenia seem to be seriously unwell and many of them will testify to that fact.

...even with skepticism about the DSM construct [of schizophrenia], many people's intuitions are that there is something illnessy about the experiences which commonly attract the diagnosis."

At the time, someone rightly pointed out that this is a weak point in the inferential chain.

Interesting argument. Not sure about the scientific validity of the "something illnessy" intuition, though. :-) http://t.co/FPSP8JdGd5

— Jane E.M. Callaghan (@JaneEMCallaghan) July 25, 2015

To some extent this does not matter, as my post was not an attempt to justify the continued "success" of the schizophrenia concept, but rather to explain it. Thus, I do not need to show that the "illnessy intuition" is scientifically valid, only that it has a hold on people's imaginations. However, if you detected a note of endorsement in my post, that is because it was there. I do not really believe in the notion of schizophrenia as illness, but unlike some critics, I do not think it is warranted to conclude that no-one who meets the diagnostic criteria is ill. In some cases the illnessy intuition is valid. Here's how.

Defining illness is slippery, and I am not going to get into philosophical debates here about how to arrive at a definition. For my purposes I don't need to. Some phenomena are so widely agreed to be illnesses that to describe them in any other way seems redundant. I could argue, for example, that leukemia is not an illness, but generally we accept it is because that framework has remained the most useful game in town.

The same appears to be true of some of the phenomena which can give rise to a diagnosis of schizophrenia. It has recently been suggested that some proportion of individuals with "schizophrenia" may actually have a form of NMDA-receptor encephalitis, a brain disorder which is treatable. If these people are not considered ill then two harms arise; they are denied effective medical treatment, and they are denied an adequate narrative account of their distress.

It is this fact that gives rise to the "illnessy intuition" in the case of schizophrenia, and for two reasons. The first is that some unknown (and possibly quite high) percentage of cases clearly arises from biological states of affairs which it will prove useful to describe as illnesses. Think not only of NMDA receptor encephalitis, but also of the conditions, and pharmacological treatments, which are yet to be discovered. The second is a sort of reasoning by analogy. If the set of symptoms associated with schizophrenia can be produced by an illness then it stands to reason that even cases which are not produced by the same phenomena might reasonably be construed as illness, pending a fuller explanation.

None of this speaks against the project of providing alternative non-medical narratives for understanding the suffering associated with psychosis. As I said in the original post, we don't yet know how (or if) all cases of schizophrenia will wind up being explained.