Regeneration by Pat Barker

Craiglockhart War Hospital, Scotland, 1917, and army psychiatrist William Rivers is treating shell-shocked soldiers. Under his care are the poets Siegfried Sassoon and Wilfred Owen, as well as mute Billy Prior, who is only able to communicate by means of pencil and paper. Rivers's job is to make the men in his charge healthy enough to fight.

Yet the closer he gets to mending his patients' minds the harder becomes every decision to send them back to the horrors of the front.
 
Pat Barker's Regeneration is the classic exploration of how the traumas of war brutalised a generation of young men.