The term mental health has become so ubiquitous in our discourse, that we barely stop to consider what it might mean. In lay terms, it is increasingly a descriptor for our emotional lives, a denoter of our problems with living.

But as a new book, The Balanced Brain by neuroscientist Camilla Nord, outlines, at an academic level, the term encapsulates multiple disciplines: neuroscience, psychoanalysis and behaviourism.