Henry's Demons, By Patrick and Henry Cockburn

One has got used to reading Patrick Cockburn's beautifully crafted, analytical and informed pieces, often from the bloodiest of war zones, which have appeared in the Independent (and the Financial Times before that) for the past 25 years. As a foreign correspondent, he has won just about every award going as he has reported from Beirut, Baghdad, Tehran, Chechnya, Jerusalem - and of course from Afghanistan, where he was writing about the Taliban when this book starts.

Henry's Demons shows a very different Patrick Cockburn, co-writing a very different kind of story, about an issue which has affected him even more than all the body-parts he has counted over a lifetime in the battle zones. He has produced a book of extraordinary candour and frankness on the most private of his family affairs: the mental illness which struck his 20-year-old son nine years ago, and which he and his wife Jan, an academic in Canterbury, have been to hell and back with since. His co-author is Henry Cockburn, an apparently happy, normal arts student in Brighton who one night, without any warning, suddenly tried to swim across the freezing estuary at Newhaven because, he said, "voices" had told him to.

He survived – just – and was diagnosed with paranoid schizophrenia, which in mental-health terms is pretty much as bad as it gets. And it got very bad indeed. After somehow managing to get home from Kabul, Patrick was informed by the consultant psychiatrist that "a third of people diagnosed with schizophrenia recover completely, one third have further attacks but show improvement, and one third do not get better".

Henry Cockburn turned out to be in the middle third, although there were years when his parent thought it could be even worse. One of the problems, normal for schizophrenics, is that never accepted there was anything wrong with him. He believed that the trees and bushes genuinely did speak to him and that his visions of tree roots responding to his touch, and voices ordering him to swim naked in the freezing water, were as real as the walls of his mental institutions.

For years he successfully fooled his nurses and doctors that he was taking his medicine, which led to an extraordinary series of episodes as he escaped again and again from the increasingly secure institutions in which he was sectioned. He later calculated that he escaped over 30 times, running off into the wild where he came within a hair's breadth of freezing to death, drowning or falling under a train.

One thing remained constant: Henry never tried to hurt anyone else. His character was that of the man in the Irish song: "Of all the harm that I've ever done, alas 'twas done to none but me." No harm maybe, but he certainly caused a lot of suffering for his parents, neither of whom could have coped without the other.

Partly as a project that might help Henry's healing process, but also to provide an insight into how mentally ill people see the world, Patrick persuaded his son to set down exactly what he experienced when he heard the voices and saw the visions. By that stage, Henry had moved up through a succession of more and more grim secure institutions, including the famous Bethlem Royal Hospital in south London, origin of the word "bedlam", and finally, as he got better, to a halfway house in south London. It is Henry's words rather than Patrick's which will make this book special for those wrestling with family members with a mental illness.

In the course of looking after Henry in these disruptive years, Patrick became something of an authority on mental illness and schizophrenia. At first, he thought schizophrenia was a mental illness which could either be cured or couldn't, but soon found it was nothing like so simple. Today, he sees it as a mental disorder which is very difficult to eliminate but which maybe Henry can learn to control.

The book ends on a hopeful yet chilling note from Henry himself: "It has been a very long road for me, but I think I'm entering the final straight. There is a tree I sit under in the garden in Lewisham which speaks to me and gives me hope."