This article discusses the recent increase in the use of solitary-like confinement, especially the rise of so-called supermax prisons and the special mental health issues and challenges they pose. After briefly discussing the nature of these specialized and increasingly widespread units and the forces that have given rise to them, the article reviews some of the unique mental-health-related issues they present, including the large literature that exists on the negative psychological effects of isolation and the unusually high percentage of mentally ill prisoners who are confined there. It ends with a brief discussion of recent caselaw that addresses some of these mental health issues and suggests that the courts, though in some ways appropriately solicitous of the plight of mentally ill supermax prisoners, have overlooked some of the broader psychological problems these units create.