This week I was saddened to read Marian Keyes's announcement that she is taking a sabbatical from writing because of crippling depression, while on Radio 4's Front Row Joyce Carol Oates admitted that she currently has no plans to write a new novel as, since the death of her husband in 2008, she lacks "the psychological strength or concentration" required.

This reminded me of the old joke about a famous clown who, suffering from depression, visits the doctor. The doctor doesn't recognise the celebrity without his make-up and says the best thing he can prescribe is a visit to the circus to watch the famous clown at work. Physician heal thyself, indeed.

For, while I don't believe that literature alone can cure depression (the importance of therapy, counselling, medication, lifestyle choices and so on should not be underestimated) I do believe that literature can help one deal with this debilitating illness. At the very least, after a period when even the idea of reading seems an alien concept, to find oneself reading – and enjoying – a book again can come as an immense relief: an indication that one is beginning to emerge from beneath a dark cloud that at one time seemed endless.

When I was going through a particularly tough time, the book that helped me was Saul Bellow's Herzog. I'm no psychologist, and everyone's reading experience is unique, so all I'm going to try to do here is explain what it was about my reading of Herzog that I found so beneficial.
To start with, I didn't plan on reading the novel (at the time I couldn't read anything) but one day I found myself plucking it – as if at random – off my shelf and from the opening lines ("If I am out of my mind, it's all right with me, thought Moses Herzog") I was utterly absorbed. This was a book I had read and reread over the years, but suddenly felt as if I was reading for the very first time. Obviously, the subject matter now had special significance, Herzog basically being about a man going through, and coming to terms with, a mental breakdown. But the novel is far from a depressing read. In fact, it is fantastically uplifting, such is Bellow's skill at rendering a potentially bleak topic in such a poignant and gently humorous way – as neatly captured in that great opening line (which for great opening lines is up there with clocks striking thirteen and stately plump Buck Mulligans descending stairwells, in my opinion.)

Just as important as the subject matter though, was the role played by Bellow's prose. It is so precise, so carefully constructed, with not a badly chosen word or comma out of place, that it demands your full attention and focuses your mind so that you are forced to concentrate completely on the novel (one cannot speed-read Herzog. Or at least I cannot). Nor is Herzog a book that can easily be put down and then picked up a week later from where you left off. You have to stick with it in order to stay on top of its non-linear narrative structure, large cast of characters and frequent forays into philosophical theorising.

And so I was able momentarily to forget my own problems and lose myself completely in the richly detailed and beautifully rendered world of the novel. I cannot describe the feeling of calm-amid-the-chaos that this generated better than Bellow himself in this sublime passage describing the demolition of a building in the middle of New York: "At the corner he paused to watch the work of a wrecking crew. The great metal ball swung at walls, passed through brick, and entered the rooms, the lazy weight browsing on kitchens and parlours. Everything it touched wavered and burst, spilled down."

This passage also illustrates another aspect of Bellow's genius (not a word to be flung around lightly): by finding poetry in the everyday and mundane, Bellow makes you view the world through new eyes, and in doing so rediscover your own place in it, thereby helping you make your first tentative steps towards rehabilitation.

It could be that I was ready to start reading again, and had I not plucked Herzog from the shelf I would have had a similar experience reading something else. But I doubt that Patrick Hamilton's Hangover Square would have had quite the same effect and I am great believer in the subconscious mind directing us towards books, films, pieces of music, and most importantly people, that turn out to be exactly what we need at the time.