The Real Flaws in Psychiatric Diagnosis 1: The Focusing Illusion

In previous posts I have been grappling with my feeling that some of the arguments used against psychiatric diagnosis are superficial or wrong. There are numerous harms associated with psychiatry, (not least of which is the use of toxic, sometimes useless medications-administered as though a psychiatric diagnosis were necessarily the same sort of thing as a disease or infection) and diagnosis sometimes takes the heat as an obvious symbolic stand in for these. In the main, it seems perfectly possible to group kinds of problem together by common aetiologies and processes they share, and then use this information to help treat them. This is all diagnosis ought to be.

However, just because it is possible to diagnose mental health problems successfully, it doesn't follow that it is the most suitable approach to grasping them. In discussing this issue with people on Twitter and other forums, I have felt that the viability of diagnosis (though not the common diagnostic system the DSM) remains intact, but its desirability, as a thing one person does to another, is a lot more questionable. The most common way of complaining about diagnosis is to describe it as a sort of "labeling" or "pigeonholing" of people. This gets dismissed by some (e.g. Paul Meehl) as basically trivial, after all, other sorts of patients get labelled too. However, there is more to labeling than first meets the eye. How we apprehend one another strongly affects how we interact, and how we interact affects how we behave and feel, both of which are obviously crucial for mental health. In this and following posts I will explore ideas from psychology and philosophy that inform the effect of labeling on human interactions, these ideas raise (but don't necessarily answer) significant questions for diagnosis:

The Focusing Illusion:

The focusing/anchoring illusion is the tendency for people to inadvertently be guided by information that is actually a good deal less relevant than they think to the decision at hand. Daniel Kahneman writes brilliantly about it in his book Thinking, Fast and Slow, and here he is in person explaining how it works far better than I can:

Kahneman is concerned here with how the focusing illusion disrupts our thinking & decision making about our own lives, but there are two reasons I think it is relevant to the question of diagnosis. The first is that it is a judgement bias that could thwart the process of successfully making a diagnosis (i.e. focusing on a less relevant piece of information and leaping to an incorrect conclusion). This is a problem that is already recognised and researched in psychiatric diagnostics (i.e. this 2009 study by Woodward et al), but, it is of less interest to me here because it is a flaw in diagnostic reasoning that could interfere with even a perfectly valid physical diagnosis. If it is accepted that diagnosis in physical medicine is useful, then any problem that is equally relevant to that field and the psychiatric field is not really a problem for psychiatry alone.

The specific danger of the focusing illusion in mental health is that, in the absence of more knowledge about a person's experience the diagnosis itself becomes the over-valued piece of information, leading to a situation in which alternative explanations for a person’s suffering are no longer considered. Once someone has been flagged as "Personality Disordered" (say) it becomes extremely easy to interpret everything they do in the light of this information (Rosenhan's classic study of psychiatric wards is of course the classic example of this). More importantly still, it becomes much harder to see what they experience in terms other than those set out by the notion of the disorder. Any readers of this blog who have been diagnosed with serious disorders like Schizophrenia or Bipolar Disorder may have their own stories to tell about how the strong medical connotations of these words can seem to prevent them from being given access to other more humanistic therapeutic input. This paper by Joanna Moncrieff (which was brought to my attention by Dr David Murphy, whose blog on psychotherapy is here) is a good illustration of the ways diagnosis can obscure rather than illuminate the complexities of people's problems.

Perhaps it's possible for psychiatric diagnosis to be helpful in spite of the focusing illusion. By necessity this is the case in physical medicine, where nobody disputes that it is generally worth knowing you have Cancer in spite of the sometimes devastating implications of that knowledge. However, psychological disorder constructs are infinitely more slippery and controversial than Cancer, and in the ongoing competition with other tricky self-relevant concepts, they are receiving a huge steroid boost by their inclusion in the DSM.    They may be responsible for obscuring other aspects of service-user's very personhood.