The jail and prison population in the United States has been multiplying exponentially for four decades. We now have almost two-and-a-half million people behind bars, and during the same years the proportion of prisoners with serious mental illness has also grown. The Treatment Advocacy Center and the National Sheriff’s Association recently released a study showing that there are ten times as many individuals with serious mental illness in our jails and prisons as there are in our state psychiatric hospitals. Mental health services behind bars have not grown apace, and as a result a large number of prisoners with serious mental illness are subject to victimization in the jails and prisons, receive inadequate mental health treatment, and are subjected to harsh conditions of confinement that exacerbate their mental illness and make their prognosis dire. There is a mental health crisis behind bars, and correctional mental health treatment requires urgent attention.