In British Clinical Psychology, "diagnosis" has itself become a dirty word, regarded as a simile for "labelling" "over-simplifying" and "pigeonholing". It has been spoken about as a malign process of linguistic colonisation, in which an individual's account of their distress is completely effaced. Psychological Formulation, a core competency of the profession is seen as the answer, a process of encapsulating service users' rich descriptions of their own psychological distress. It has been proposed as an alternative not only by the expected team of UK and New Zealand psychologists and psychiatrists but also on philosophical grounds by Belgian psychoanalyst Stijn Vanheule (though it has been noted by David Pilgrim and Timothy Carey that it can be read as an attempt by Clinical Psychology to further affirm its professional status).
A naive observer would be forgiven for feeling puzzled. Surely a diagnostic classification and an explanatory story are not incompatible? Indeed, even Lucy Johnstone, a vociferous opponent of diagnosis and author of a leading text on formulation, has pointed out on Twitter that Formulations can, for the purposes of medical record keeping, be shortened to a version agreed with service user such as "Reaction to severe early trauma, compounded by recent bereavement". She has also said that "Schizophrenia' can often (not always) be replaced by 'dissociative reaction to severe trauma'"; a statement which seems to imply that one construct can be more or less replaced by another.
The real problem with "Diagnosis", in the context of "Diagnostic and Statistical Manual" is that it is not really a diagnosis at all. When you type the word into Google, the first result is the Wikipedia page, which says that "Diagnosis is the identification of the nature and cause of anything". DSM is a text largely devoid of causes and certainly doesn't get into the nitty gritty question of the nature of the phenomena it claims to codify. This is a point that proponents of Formulation have made, and I suspect they would agree that what they are proposing is much closer in spirit than is the DSM to an actual diagnosis.
This suggests that the distinction between "Diagnosis" and "Formulation" is a false one. Evidently the two practices should, in an ideal world, bleed into one another. There is nothing wrong with Diagnosis per se, it is just that the manual we currently use to do it is actually doing something else entirely (namely, bland and often unworkable classification). Formulation does a better job, but, from what I know about it, has no systematic way of incorporating information about the psychology and biology of the person to whom the life events has happened. A third alternative is the PDM, a psychoanalytic, American competitor which manages to integrate psychodynamic information about the person (their chosen style for coping with strong affect, their manner of relating) with an openness to a consideration of environmental factors and life events (their parenting, trauma etc).
Is this a dialectic that can be successfully resolved, or is the debate so bound up in territorial warfare that mental health professionals will always revert to the position dictated by their ideological prejudices?