Over the past four decades, prisons across the country have increasingly relied on solitary confinement—isolating prisoners in small poorly-lit cells for 23-24 hours per day—as a disciplinary tool for prisoners who are difficult to manage in the general population. But research has shown that these conditions cause serious mental deterioration and illness. When these prisoners are eventually released from solitary confinement, they have difficulties integrating into the general prison population into life on the outside.