Transcendent Kingdom by Yaa Gyasi

As a child Gifty would ask her parents to tell the story of their journey from Ghana to Alabama, seeking escape in myths of heroism and romance. When her father and brother succumb to the hard reality of immigrant life in the American South, their family of four becomes two - and the life Gifty dreamed of slips away. Years later, desperate to understand the opioid addiction that destroyed her brother's life, she turns to science for answers. But when her mother comes to stay, Gifty soon learns that the roots of their tangled traumas reach farther than she ever thought. Tracing her family's story through continents and generations will take her deep into the dark heart of modern America.