Paul Gionfriddo's son Tim is one of the "6 percent"--an American with serious mental illness. He is also one of the half million homeless people with serious mental illnesses in desperate need of help yet underserved or ignored by our health and social-service systems.

In this moving, detailed, clear-eyed expose, Gionfriddo describes how Tim and others like him come to live on the street. Gionfriddo takes stock of the numerous injustices that kept his son from realizing his potential from the time Tim first began to show symptoms of schizophrenia to the inadequate educational supports he...