Theresa Larsen's son, Matthew, comes to her with a cut on his hand, explaining it away as an accident with a pocket knife. But as she cleans and treats the wound, she discovers dozens of slashes covering both of his arms. Thus begins Larsen's compelling personal memoir about what it's like to be the parent of a mentally ill teenager.

"Cutting the Soul" offers a firsthand look at mental illness, both financially and emotionally. Matthew, fourteen years old when he starts cutting, goes on to face other hardships, including suicide attempts, severe depression, and multiple stays in...