The Body Keeps the Score, Bessel van der Kolk, published by Penguin.
It is a profound work on the nature, causes, and treatment of post-traumatic stress disorder, and how it affects both mind and body.
It is, for me, a ground-breaking (and I wouldn't say that unless it was deserved) work.
And by PTSD, we are not simply talking about the effects of war and disaster, but also of the various forms of abuse that leaves both children and adults struggling to cope with life.