Canongate has signed Unspeakable: The Things We Cannot Say by Harriet Shawcross, saying it will be the publisher's lead title in autumn 2018.
Publisher Jenny Todd acquired world rights from Kirsty McLachlan at David Godwin Associates.
The publisher said: "We have all on occasion been lost for words - but what makes some aspects of life truly unspeakable? And what happens when we find we have nothing to say? From the inexpressible trauma of trench warfare, to the taboo of coming out, Unspeakable, explores how and why words fail us. Part memoir, part journalism, in Unspeakable documentary-film maker Harriet Shawcross travels across the world to meet people living in silence.
"She examines how we have tried to coax the words out - from public hypnotism of hysterical mutes in 19th century Paris, to the growth of talking therapy in the shadow of World War One. And she looks at how we have made space for the secret and taboo - from the establishment of the Samaritans in an East London crypt, to her own experiences of coming out in her 30s, and articulating what she imagined to be unspeakable."
Todd said: "In Unspeakable, Harriet Shawcross gives voice to the silent, and we are so delighted to be helping her to do that. Unique, heartfelt and deeply moving".