David: One of the worst things of having a sadness upon you, of suffering from depression is the terrible inertia it brings. The maddening sense of knowing all the things you need to do whilst being sapped of the will to do them. The resistance that comes from the Black Dog – the biting tug that holds you back – is such a horrid thing, but being able to name it, to have a word for it, sometimes seems to be the first step of tackling it.

Jo: Amongst my books on art, maps, guides, geography, artists – there is a slim book called ‘Living with a Black Dog’. I can’t cope with a lot of text, and this is like a picture book for adults. Every so often the Black Dog has roamed into parts of my life, and I found solace in this book. Because my mental state so affects my work, I wish I understood it more, at times it behaves as randomly as our rescue dog. I think you’re right, naming it is the first step. Our black (with a little bit of white), rescue dog is called Stig, from ‘Stig of the Dump’.