PSYCHIATRIC TAXONOMIES
It would be nice if the world of mental health fell neatly into a taxonomy. It would be nice if we could, as Plato wrote, carve nature at its joints:1
‘Plato famously employed this “carving” metaphor as an analogy for the reality of Forms (Phaedrus 265e): like an animal, the world comes to us predivided. Ideally, our best theories will be those which “carve nature at its joints”.’2
We would find it so much easier to cope if all human suffering could be allocated to a relevant, and distinct, category that encapsulated the likely cause and course of the disease. However, in psychiatry, the landscape is not so simple. It’s just easier in many ways to pretend it is.
Psychiatric taxonomies such as DSM-5 and ICD-11 help us to categorise mental illness into a series of diagnoses based on observable …