Across the country, states are waking up to the fact that we must address our overreliance on solitary confinement. Long-term isolation costs too much, does nothing to rehabilitate prisoners, and exacerbates mental illness - or even causes it in prisoners who were healthy when they entered solitary. Officials in some states that formerly relied heavily on solitary confinement are now realizing that they should use public resources on proven policies that promote safe communities and fair treatment, and are successfully reducing the use of solitary - at the same time saving their states millions and reducing violence in the prisons. It's time for more states, and the federal Bureau of Prisons, to follow suit.