Every day, between 41,000 to 48,000 inmates, many Of them seriously mentally ill (SMI) inmates, live in solitary confinement (solitary), which represents the most severe punishment thal inmates can.jace asidefrom execution. With solitary, prison Ollicials segregate inmates from the general prison population and deprive them of human contact and sensory stimulationfor disciplinary or secitrity reasons. Modern day research has confirmed its negative mental health impact, especially on SMI inmates, which can lead to suicide. The Supreme Court's traditional prison conditions jurisprudence grounds itself in the Eighth Amendment's cruel and unusual punishments clause and the evolving standards of decency. It protects against the substantial risk of serious harm to which prison omcials are deliberately indit.jerent. SMI inmates in solitary often advance two claims, that officials impose inhumane prison conditions and provide inadequate mental health care. Some cases, including afew class actions, have declared placing SMI inmates in solitary unconstitutional and denounced ineffective screening that led to placing SMI inmates in solitary. However, before overcoming their customary deference to prison omcials, courts required egregious levels of harm. The courts' proportionality review Of sentences, also based on the Eighill Amendment and evolving standards of decency, offers an alternative doctrine that better equips courts to overcome their customary deference to prison officials. Courts have used proportionality review, for exaniple, to ban the execution of the intellectually disabled and the doctrine can likewise lead to a broad ban on placing SMI inmates in solitary. Practically speaking, this entails considering the weight ofcurrem policy and the degree to which placing SMI inmates in solitary satisfies penological goals, to wit, retribution. incapacitation, deterrence, and rehabilitalion. Also. professional organizations, international authorities, and Colorado, a good example ofsolitary rejbrm, all support a broad ban on placing SMI inmates in solitary. [ABSTRACT FROM AUTHOR]